How to Measure Bolt Patterns on Wheels: A Complete Guide

Understanding how to measure the bolt pattern on your wheels is crucial for any wheel upgrade or replacement. Whether you're shopping for aftermarket rims, replacing a damaged wheel, or verifying fitment, knowing how to accurately determine your bolt pattern saves time, money, and potential safety issues. This guide walks you through the process step by step.

What Is a Bolt Pattern?

A bolt pattern (also called bolt circle or PCD — Pitch Circle Diameter) describes two measurements:

1. The number of lug holes on the wheel
2. The diameter of the circle formed by the centers of those lug holes

For example, a 5x114.3 bolt pattern means 5 lug holes on a circle with a 114.3mm diameter. For a deeper explanation, see our bolt pattern fitment guide.

Tools You'll Need

• Tape measure or ruler (millimeter markings preferred)
• Bolt pattern gauge (optional but most accurate)
• Caliper (for precise measurements)
• A straight edge or piece of string
• Calculator (for converting inches to millimeters)

Measuring Even-Lug Bolt Patterns (4, 6, or 8 Lugs)

Even-numbered bolt patterns are the easiest to measure because you can measure directly across from one bolt hole to the opposite one.

Step-by-Step:

1. Identify two directly opposite bolt holes — Pick any bolt hole, then find the one straight across from it (180° away).
2. Measure center to center — Place your tape measure at the exact center of one bolt hole and measure straight across to the exact center of the opposite bolt hole.
3. Record the measurement — This is your bolt circle diameter.

4-Lug Example

If you measure 100mm from center to center across two opposite bolt holes, your bolt pattern is 4x100.

6-Lug Example

If you measure 139.7mm across opposite bolt holes on a 6-lug wheel, your bolt pattern is 6x139.7 (very common on trucks).

8-Lug Example

Same principle — measure across two opposite lugs. Common measurements include 165.1mm (8x165.1) and 170mm (8x170).

Measuring 5-Lug Bolt Patterns

Five-lug patterns are trickier because no two bolt holes are directly opposite each other. You can't simply measure straight across. Here are two methods:

Method 1: Back-to-Far-Center Measurement

This is the most common DIY method:

1. Choose any bolt hole as your starting point
2. Measure from the back (far edge) of that bolt hole to the center of the bolt hole farthest away (skip one hole — go to the one that's roughly across from you)
3. This measurement equals the bolt circle diameter

For example, if you measure 114.3mm, your bolt pattern is 5x114.3.

Method 2: Adjacent Bolt Hole Math

1. Measure the distance between the centers of two adjacent bolt holes
2. Multiply by the conversion factor: 1.701
3. The result is your bolt circle diameter

Example: Adjacent bolt holes are 58.5mm apart → 58.5 × 1.701 = 99.5mm ≈ 5x100

Method 3: Bolt Pattern Gauge

The easiest and most accurate method. A bolt pattern gauge has pre-drilled holes for common patterns. Simply place it over your lug studs — the pattern that aligns perfectly is your bolt pattern.

Common Bolt Patterns Quick Reference

After measuring, compare your result to these common bolt patterns:

Metric vs. Imperial Bolt Patterns

Bolt patterns are expressed in both metric (millimeters) and imperial (inches), and some patterns have both designations:

When shopping for wheels, make sure you're comparing the same unit system. 5x4.5" and 5x114.3mm are the same pattern.

Measuring Without Removing the Wheel

You don't always need to remove the wheel to measure the bolt pattern:

1. Through the center cap — Many center caps pop off, exposing the lug studs for measurement
2. Using lug studs — Measure between the studs on the hub with the wheel removed (easiest during a tire change)
3. From the back — If you can access the back of the wheel, the bolt holes are visible for measurement
4. Use a vehicle database — Look up your year/make/model online if you just need to confirm

Why Accurate Measurements Matter

Getting your bolt pattern wrong leads to real problems:

• Wheels that won't mount — The bolt holes simply won't align with your lug studs
• Forced fitment damage — Attempting to force a close-but-wrong pattern damages both the wheel and lug studs
• Unsafe driving — A bolt pattern that's off by even a few millimeters means the wheel isn't properly centered, causing vibration, uneven wear, and potential wheel failure
• Wasted money — Most wheel retailers don't accept returns on mounted wheels

Other Measurements to Take While You're At It

Since you're already measuring your wheels, capture these specs too — you'll need them when shopping:

• Wheel diameter — Measure the bead seat (where the tire sits), not the outer lip
• Wheel width — Distance between the inner bead flanges
• Offset — Stamped on the back of the wheel (e.g., ET45)
• Center bore — Diameter of the center hole
• Lug nut seat type — Conical, ball, or flat

For offset details, check our wheel offset calculator.

Frequently Asked Questions

How do I measure a 5-lug bolt pattern accurately?

The most reliable method is measuring from the back edge of one bolt hole to the center of the bolt hole farthest from it (not the adjacent one). Alternatively, measure between two adjacent bolt hole centers and multiply by 1.701. A bolt pattern gauge tool is the most accurate option.

What if my measurement doesn't match any standard bolt pattern?

Your measurement is likely slightly off — bolt patterns follow strict industry standards. Round to the nearest common pattern. For example, 113mm is actually 5x112, and 115mm is actually 5x114.3. When in doubt, try a bolt pattern gauge or look up your vehicle's specifications.

Can I measure the bolt pattern with the tire on?

Yes, if you can access the lug studs (remove the center cap or use the studs visible around the edge). However, measurements are more accurate with the wheel removed.

What's the difference between bolt pattern and bolt circle?

They're the same thing. Bolt pattern, bolt circle, PCD (Pitch Circle Diameter), and lug pattern are all terms for the same measurement — the number of bolt holes and the diameter of the circle they form.

Do I need to measure bolt pattern on both front and rear wheels?

On most vehicles, front and rear bolt patterns are identical. However, some vehicles (rare) use different patterns front and rear. It's worth verifying if you're unsure, especially on older or modified vehicles.

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Accurate bolt pattern measurement is the foundation of a successful wheel upgrade. Take your time, measure twice, and when in doubt, use a bolt pattern gauge or look up your vehicle's specifications.

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