V Belt Size Chart| A, B, C, 3V, 5V Belt Sizes Explained

Quick Answer

A V belt size is determined by its profile, cross-section, length and pulley compatibility. Common industrial V belt profiles include classical A, B, C and D sections, as well as narrow-section 3V, 5V and 8V profiles.

For replacement, do not choose a V belt by length alone. The correct belt must match the required profile, top width, height, length measurement system, pulley groove and application.

If you are new to V belts, start with What Is a V-Belt? Complete Guide to Types, Construction, Materials, Sizes and Applications.

V Belt Size Chart

The following chart provides a practical reference for common V belt profiles.

These are approximate nominal profile dimensions for identification. Exact finished dimensions can vary according to the applicable belt standard, construction and product series.

For example, REALSHOW’s Classical V-Belt range covers common A, B, C and D profiles as well as other classical sections. See the Classical V-Belt product range for product-level specifications.

What Does V Belt Size Mean?

A V belt size is not simply the circumference of the belt.

A complete V belt specification can include:

• Belt profile

• Top width

• Height

• Length

• Length measurement basis

• Construction

• Pulley compatibility

• Application requirements

For example, an A-section belt and a 3V belt can have relatively similar overall proportions, but they belong to different profile systems and are designed for different pulley grooves.

This means a belt should never be selected only because its measured length appears correct.

A reliable replacement process is:

Profile → Dimensions → Length → Construction → Pulley → Application

V Belt Dimensions: Width, Height and Length

The three most commonly discussed V belt dimensions are:

Top Width

Top width is measured across the widest part of the belt.

It is one of the most useful dimensions for identifying the belt profile.

Belt Height

Belt height is measured vertically from the top surface to the bottom of the V-shaped cross section.

Width and height should be evaluated together because some profiles can have similar widths but different heights.

Belt Length

Belt length is more complicated because different V belt families can use different length measurement systems.

Depending on the belt type, you may encounter:

• Inside length

• Outside length

• Reference length

• Datum length

• Effective length

Therefore, the number printed on a belt should always be interpreted together with its profile and belt family.

For detailed identification, see How to Identify a V-Belt: V-Belt Number Meaning and Size Guide.

Classical V Belt Size Chart: A, B, C and D

Classical V belts are widely used in industrial machinery and conventional power transmission systems.

The larger the profile, the greater the cross-sectional area available for power transmission. However, a larger belt is not automatically a better belt.

The profile must match the pulley groove and drive design.

REALSHOW’s classical V belt range includes multiple classical sections, allowing distributors and industrial buyers to source different profiles from one manufacturer.

3V, 5V and 8V V Belt Size Chart

3V, 5V and 8V are narrow-section V belt profiles commonly used for power transmission where compact drive dimensions and higher power density are important.

These dimensions are approximate identification references. Always confirm the exact profile specification before production purchasing.

For a broader explanation of classical, narrow and cogged V belts, see V-Belt Types Explained: Classical vs Narrow vs Cogged.

V Belt Size Chart for SPZ, SPA, SPB and SPC

Many industrial buyers also encounter metric narrow-section V belts.

Common profiles include:

These profiles should not be confused with classical A, B, C and D sections simply because some dimensions appear similar.

The pulley groove must correspond to the belt profile.

The belt length must also be interpreted according to the applicable measurement system.

Although belt dimensions help identify a profile, they do not by themselves prove that two belt types are interchangeable. Learn more about SPB belt vs B-section V-belt compatibility before choosing a substitute.

A vs B vs C vs D V Belt Sizes

The main dimensional difference between classical profiles is their cross-sectional size.

A larger profile generally supports higher power transmission, but the correct selection depends on the complete drive design.

The pulley, center distance, speed, load and operating environment must all be considered.

3V vs A V Belt

3V and A belts should not be treated as interchangeable.

Although their overall dimensions may appear relatively close, they belong to different profile systems.

The pulley groove is one of the most important reasons these profiles cannot simply be substituted.

5V vs B V Belt

B and 5V are also different belt profiles.

Do not select between B and 5V solely according to measured width.

The belt profile and pulley groove must be matched.

8V V Belt Dimensions

8V is a large narrow-section V belt profile designed for demanding power transmission applications.

Its approximate nominal dimensions are:

• Top width: 25–26 mm

• Height: approximately 23 mm

Because of its larger cross section, 8V is normally associated with larger industrial drives.

The correct pulley groove and drive design must be confirmed before replacement.

Classical V Belts vs Narrow V Belts

Classical V belts and narrow V belts use different cross-sectional designs.

Classical profiles include:

• A

• B

• C

• D

• E

Narrow profiles can include:

• SPZ

• SPA

• SPB

• SPC

• 3V

• 5V

• 8V

Narrow belts can provide high power transmission capability within a relatively compact drive design, but that does not mean they are universal replacements for classical belts.

The belt must always be selected according to the pulley and application.

V Belt Length: Inside, Outside and Effective Length

One of the most common causes of V belt identification errors is misunderstanding the length designation.

Inside Length

Inside length is measured along the inner surface of the belt.

Outside Length

Outside length is measured around the outer circumference of the belt.

Reference or Datum Length

Reference or datum length is measured at a defined position within the belt profile according to the relevant standard.

Effective Length

Effective length is another standardized measurement used by certain belt families.

These values are related, but they are not interchangeable.

Therefore:

Do not convert a V belt number into a physical length using a generic formula unless the belt family and measurement standard are known.

This is especially important when comparing classical inch-section belts with metric narrow-section belts.

How to Identify a V Belt Size

When the original marking is readable, start with the complete belt marking.

Look for:

• Letters

• Numbers

• Profile codes

• Length codes

• Construction suffixes

• Manufacturer markings

If the marking is missing, use a combination of physical measurements.

The identification process should be:

Marking → Profile → Width → Height → Length → Construction → Pulley → Application

For a complete step-by-step process, see How to Identify a V-Belt.

How to Measure a V Belt

If the belt marking is unreadable, measure the belt carefully.

1. Measure the Top Width

Measure the widest part of the belt.

Do not measure along the angled sidewall.

2. Measure the Height

Measure vertically from the top surface to the bottom of the V-shaped section.

3. Measure the Length

Determine whether the required reference is:

• Inside length

• Outside length

• Effective length

• Reference/datum length

Do not assume that the physical circumference you measure is automatically the number used in the belt designation.

For general belt measurement principles, see How to Measure an Automotive Belt Without a Part Number.

4. Inspect the Construction

Check whether the belt is:

• Wrapped

• Raw edge

• Cogged

• Narrow wedge

• Banded

• Double V

5. Inspect the Pulley

Confirm the pulley groove profile and condition.

A worn pulley can make a correctly manufactured belt appear incorrectly sized.

How to Identify a V Belt Without Markings

When the marking has disappeared, do not rely on one measurement.

Use:

• Top width

• Height

• Length

• Cross section

• Construction

• Pulley groove

• Application

• Original equipment information

For example, a measured top width near 17 mm may indicate a B-section belt, but width alone does not prove the identification.

The height, length system and pulley should also be checked.

V Belt Construction and Material

V belt dimensions determine whether a belt fits the mechanical system, but material and construction influence how the belt performs.

A typical V belt may contain:

1. Rubber compound

2. Tensile cord

3. Compression section

4. Fabric covering

Important performance characteristics include:

• Tensile strength

• Flexibility

• Heat resistance

• Wear resistance

• Aging resistance

• Dimensional stability

For more information, see the V-Belt Material Guide.

Wrapped vs Cogged V Belts

V belts with the same nominal profile can still use different constructions.

Common constructions include:

• Wrapped V belts

• Raw edge V belts

• Raw edge cogged V belts

• Narrow wedge belts

• Banded V belts

• Double V belts

A cogged V belt contains molded notches that improve flexibility around smaller pulley diameters.

However, a cogged belt should not automatically replace a smooth belt simply because the profile and length appear similar.

The original drive design and manufacturer’s specification should be checked.

V Belt and Pulley Compatibility

A V belt and pulley must work as a matched system.

Check:

• Belt profile

• Groove profile

• Groove angle

• Groove width

• Pulley diameter

• Pulley condition

• Alignment

• Belt tension

An incorrect profile can cause:

• Slipping

• Excessive heat

• Abnormal wear

• Vibration

• Reduced power transmission

• Premature failure

A new belt cannot compensate for a severely worn pulley.

Correct belt dimensions and pulley compatibility are only part of a reliable drive setup; installed tension must also meet the specified requirements. See our guide to measuring V-belt tension using force-deflection and frequency-based methods.

How to Choose the Correct V Belt

For reliable V belt selection, follow this sequence.

Step 1: Identify the Profile

Determine whether the belt is:

• A

• B

• C

• D

• 3V

• 5V

• 8V

• SPZ

• SPA

• SPB

• SPC

• Another specified profile

Step 2: Confirm the Length

Determine which length system applies.

Step 3: Confirm the Construction

Identify whether the belt is wrapped, cogged, raw edge, narrow wedge or another construction.

Step 4: Check the Pulley

Confirm the groove profile, diameter, condition and alignment.

Correct V-belt dimensions are only one part of a reliable drive installation. The relative position of the driving and driven pulleys also matters. Learn how to identify parallel, angular, and combined misalignment in our industrial V-belt alignment measurement guide.

Step 5: Check the Application

Consider:

• Power

• Speed

• Load

• Temperature

• Dust

• Oil

• Moisture

• Operating hours

Step 6: Confirm the Supplier Specification

For commercial purchasing, provide the supplier with the belt marking, dimensions, application and quantity.

For a more detailed selection process, see How to Choose the Right V-Belt.

What a V Belt Size Chart Cannot Tell You

A size chart is an identification tool, but it cannot determine every aspect of belt suitability.

A chart cannot by itself tell you:

• Whether the pulley is worn

• Whether the belt construction is suitable

• Whether the belt compound matches the application

• Whether the drive is correctly aligned

• Whether the belt tension is correct

• Whether the belt has sufficient power capacity

• Whether the operating temperature is acceptable

• Whether the belt is suitable for oil or chemical exposure

Therefore, a size chart should be used as the first step in identification, not the entire selection process.

V Belt Size Selection Mistakes

Choosing Only by Length

A correct length does not guarantee a correct profile.

Assuming Similar Profiles Are Interchangeable

A and 3V, or B and 5V, are not automatically interchangeable.

Ignoring the Length Measurement System

Inside, outside and effective lengths are different references.

Measuring Only Width

Width should be considered together with height and profile.

Ignoring Pulley Wear

A worn pulley can cause poor belt seating and premature failure.

Mixing Different Constructions

Wrapped, cogged and raw-edge belts can have different operating characteristics.

Selecting Only by Lowest Price

For distributors and wholesalers, poor dimensional consistency or premature failure can result in returns, complaints and higher total cost.

V Belt Selection for B2B Buyers

For distributors, wholesalers and importers, a V belt size chart is only the starting point.

When requesting a quotation, provide:

If you are sourcing V belts for industrial applications, see the Industrial Belt product range.

For manufacturer capability, see Industrial Belt Manufacturer.

Classical V Belt Products

REALSHOW supplies classical V belts covering multiple common profiles.

The product range includes:

• Z

• A

• B

• C

• D

• E

• F

For product specifications and available profiles, see the Classical V-Belt product range.

This product-level page is particularly useful for distributors who need to move from general V belt sizing information to specific belt sourcing.

V Belts for Industrial Applications

V belts are widely used in:

• Pumps

• Fans

• Compressors

• HVAC systems

• Agricultural machinery

• Manufacturing equipment

• Production machinery

• Mechanical transmission systems

Different applications require different combinations of:

Profile + length + construction + material + pulley + operating conditions

This is why an industrial V belt should be selected according to the complete drive system rather than the belt number alone.

For applications that require an open belt length or a specialized joining arrangement, conventional V-belt selection guidelines may not cover every specification. Our guide to punched open-ended V-belting sizes and identification explains how to verify the profile, required length, punched-hole pattern, and connection requirements before sourcing the belt.

Automotive V Belts vs Industrial V Belts

V belts are also used in automotive applications, but automotive and industrial belt selection should not automatically be treated as identical.

Industrial V belts are generally selected according to mechanical drive requirements such as:

• Power

• Speed

• Pulley diameter

• Center distance

• Load

• Operating environment

Automotive V belts are designed around vehicle-specific accessory drive requirements.

For automotive V belt products, see the Automotive V-Belt product category.

For the wider automotive belt system, see the Automotive Belt Guide.

Manufacturer Perspective: Why V Belt Dimensions Matter

From a manufacturing perspective, dimensional accuracy is not simply about making a belt look correct.

The finished belt must maintain controlled geometry so that:

• The belt seats correctly in the pulley

• Load is distributed properly

• Power transmission remains stable

• Tension remains consistent

• Wear is controlled

• Service life is predictable

Important manufacturing controls can include:

• Top width

• Belt height

• Belt length

• Cord position

• Rubber distribution

• Mold geometry

• Vulcanization conditions

• Finished-product inspection

For B2B buyers, dimensional consistency is particularly important because distributors and wholesalers need replacement belts that perform consistently across repeated orders.

Choosing a V Belt Manufacturer

For industrial distributors and wholesalers, selecting a manufacturer involves more than comparing unit prices.

A capable V belt manufacturer should be able to support:

• Stable dimensional control

• Consistent rubber compounds

• Reliable reinforcement

• Multiple belt profiles

• Production consistency

• Quality inspection

• OEM/private-label requirements

• Export packaging

• Technical communication

REALSHOW manufactures automotive and industrial belts and supplies customers in international aftermarket and OEM markets.

For automotive belt manufacturing capability, see Automotive Belt Manufacturer China.

For customized automotive belt projects, see OEM Automotive Belt Manufacturer.

V Belt Size Chart FAQs

What is the most common V belt size?

There is no single universal V belt size. A, B, C and D are common classical profiles, while SPZ, SPA, SPB, SPC, 3V, 5V and 8V are common narrow-section profiles.

What is the size of an A V belt?

An A-section V belt is approximately 13 mm wide and 8 mm high.

What is the size of a B V belt?

A B-section V belt is approximately 17 mm wide and 11 mm high.

What is the size of a C V belt?

A C-section V belt is approximately 22 mm wide and 14 mm high.

What is the size of a D V belt?

A D-section V belt is approximately 32 mm wide and 19 mm high.

What is a 3V V belt?

3V is a narrow-section V belt profile with an approximate top width of 9.5–10 mm and height of about 8 mm.

What is a 5V V belt?

5V is a narrow-section V belt profile with an approximate top width of 15–16 mm and height of about 13 mm.

What is an 8V V belt?

8V is a heavy narrow-section V belt profile with an approximate top width of 25–26 mm and height of about 23 mm.

Can I replace an A belt with a 3V belt?

Not automatically. A and 3V belong to different profile systems and require compatible pulley grooves.

Can I replace a B belt with a 5V belt?

Not automatically. B and 5V have different cross-sectional geometries and pulley requirements.

How do I know what size V belt I need?

Identify the belt profile, width, height, length, construction and pulley groove. Then confirm the application’s power, speed, load and environmental requirements.

Does V belt length equal outside circumference?

Not necessarily. V belts may be specified using inside length, outside length, effective length or reference/datum length depending on the belt family.

Can I identify a V belt by measuring only its width?

No. Width is useful, but accurate identification should also consider height, length, construction, pulley groove and application.

How do I identify a V belt without a number?

Measure the top width, height and appropriate length, identify the cross section, inspect the construction and confirm the pulley groove.

Are V belt sizes interchangeable between manufacturers?

Not automatically. Even when nominal dimensions appear similar, construction, length basis and product specifications may differ.

What information should I send a V belt manufacturer?

For an accurate quotation, provide the belt number, profile, dimensions, application, quantity, photos, pulley information and any available OEM reference.

Conclusion

A V belt size chart is useful for identifying the basic cross section, but correct V belt selection requires more than matching one dimension.

The most reliable process is:

Profile + width + height + length basis + construction + pulley + application

For classical V belts, A, B, C and D are important reference profiles. For narrow-section drives, 3V, 5V, 8V and SPZ/SPA/SPB/SPC profiles are commonly encountered.

For industrial buyers, the safest sourcing process is to provide the manufacturer with the complete belt marking, dimensions, application, pulley information and required quantity.

For distributors, wholesalers and OEM buyers, accurate dimensional control and consistent manufacturing are just as important as the nominal belt size.

If you are sourcing V belts for industrial or aftermarket applications, REALSHOW can support different belt profiles and customized supply requirements as an automotive and industrial belt manufacturer.