Lug pattern on rims is identified by lug count and pitch circle diameter, measured across the bolt holes with the right method for your lug count.
Your wheels only fit when the bolt circle matches your hub. This guide gives clear steps to read the pattern on any rim, measure it with common tools, and match it to the vehicle. You’ll also see where people slip up, how to read sizes like 5×114.3, and the fast way to confirm a tricky five-lug wheel.
What Lug Pattern Means
The lug pattern, also called bolt pattern or PCD, combines two values: the number of lugs and the pitch circle diameter of those lugs. A size like 5×114.3 means five studs on a circle that is 114.3 mm across. Domestic listings may show inches, such as 5×4.5, which equals 5×114.3. Get either part wrong and the wheel won’t seat cleanly, which can lead to shake, uneven wear, or hardware stress.
How to Tell Lug Pattern on Rims: Fast Overview
Grab a tape measure or calipers, a straight edge, and a marker. Count the holes, then measure the circle as described in the steps below. Convert inches to millimeters when needed. Match the result to a standard size from the first table.
| Lug Count | Common PCDs (mm / inch) | Typical Applications |
|---|---|---|
| 4-lug | 4×100 (3.94″), 4×108 (4.25″), 4×114.3 (4.5″) | Compact cars, older imports, light trailers |
| 5-lug | 5×100 (3.94″), 5×112 (4.41″), 5×114.3 (4.5″), 5×120 (4.72″) | Many sedans, crossovers, European models |
| 6-lug | 6×114.3 (4.5″), 6×120 (4.72″), 6×139.7 (5.5″) | Light trucks, body-on-frame SUVs |
| 7-lug | 7×150 | Specialized fleets |
| 8-lug | 8×165.1 (6.5″), 8×170, 8×180 | Heavy pickups and vans |
| 10-lug | 10×225, 10×285.75 | Medium duty, commercial use |
| Center-lock | Single hub nut | Motorsport, select performance cars |
Step-By-Step: Measure Any Lug Pattern
Tools You Can Use
A flexible tape, Vernier calipers for accuracy, a straight edge, and a calculator for unit conversion. A bolt pattern gauge speeds things up, yet the tape method works when you measure the correct points. If you’re new to this, skimming a pro explainer helps—see Discount Tire’s concise bolt pattern guide and Tire Rack’s visual walkthrough on how to measure wheel bolt pattern.
Four-Lug And Six-Lug Wheels
Count the lugs. Place the straight edge across two holes that sit directly opposite. Measure center-to-center across the circle. That distance is the PCD. Repeat once to confirm the reading and write it down in millimeters.
Five-Lug Wheels
Five studs don’t sit opposite each other, so measuring edge to edge gives a false reading. Pick the center of one hole, then measure to the imaginary line that bridges the two holes across the wheel. Many tech sheets describe this as measuring “across the circle through the gap.” If your reading falls near two close sizes, confirm with a PCD gauge.
Eight-Lug And Ten-Lug Wheels
Use the same across-the-circle approach as six-lug. With ten-lug commercial patterns, confirm both the PCD and the stud size, since many hubs share the same bolt circle but use different hardware.
Lug Count Vs. PCD: Read The Number The Right Way
Every listing prints lug count first, then the circle. So 6×139.7 means six lugs on a 139.7 mm circle. Inch formats use the same order, such as 6×5.5. If you measured in inches, multiply by 25.4 to get millimeters, which is the standard in most catalogs and fitment databases.
Close Variation: Telling Lug Pattern On Rims With A PCD Gauge
A PCD gauge slides across the holes and locks on the circle. It removes guesswork on five-lug rims and helps with odd counts like seven or ten. Many shops keep one on the wall, and portable rulers are affordable for home garages. This single tool saves time when two sizes are close, like 5×110 vs. 5×112 vs. 5×114.3.
Measure On The Vehicle Or Off The Vehicle
On-Vehicle Method
Turn the wheel so two holes line up horizontally. For even counts, measure center-to-center across the face. For five-lug, measure from the center of one stud to the midpoint between the two across the circle. Avoid brake dust caps and center caps that block the tape; pull them if needed.
Bench Method
Lay the rim face down on a bench. Mark the centers of two opposite holes (skip this step on five-lug). Place the straight edge through both marks and measure the distance between centers. On five-lug, mark one hole center, then measure to the midpoint of the gap across the circle. Add a second reading at a new position and average if your first pass was rough. If you ever wondered how to tell lug pattern on rims with only a tape and sharpie, this is the quick approach that works in a pinch.
Match Your Measurement To A Known Size
Once you have the number, compare it to common sets. If you read 4.5 inches across, that equals 114.3 mm, so a notation like 5×4.5 matches 5×114.3. When your five-lug reading sits near 110 mm or 112 mm, confirm with a gauge or a fitment database, since those sizes can trick a quick tape read. Many sellers list both inch and millimeter values; pick one system and stay with it through the process.
Avoid These Common Fitment Mistakes
Mixing Inch And Metric Notation
Parts sites often show both. Convert the number and match like for like before ordering. Never pair a 5×112 hub with a 5×114.3 wheel. That mismatch won’t seat correctly even if the nuts start threading.
Ignoring Center Bore And Hub Style
Hub-centric wheels seat on the hub’s spigot. Lug-centric wheels center on the nuts. A rim can share the correct PCD yet still shake if the center bore is off. Hub rings solve a larger wheel bore on a smaller hub, but they can’t fix a wrong bolt circle.
Guessing On Five-Lug Wheels
5×110, 5×112, and 5×114.3 sit close. If your tape read lands between two sizes, use a gauge or check a fitment database by make, model, and year. A few extra minutes here prevents returns and wasted trips.
Skipping Seat Style And Stud Size
Conical seats, ball seats, and mag seats look similar at a glance. The wrong seat can loosen under load. Match the seat profile and stud diameter listed by the vehicle maker or wheel brand.
Unit Conversion Shortcuts
Common inch circles and their metric matches: 4.25″ = 108 mm, 4.5″ = 114.3 mm, 4.75″ = 120.65 mm, 5.5″ = 139.7 mm, 6.5″ = 165.1 mm. Round to one decimal place when you see repeating fractions. If you prefer mental math, multiply inches by 25 and add a smidge; then confirm with a calculator.
Decoding Stamps, Castings, And Part Numbers
Flip the rim and scan the back of a spoke or the barrel. You’ll often see size (like 18x8J), offset (ET45), and a center bore number. Some castings add the bolt circle in millimeters. If the pattern isn’t printed, the other specs still help you match the right wheel once you know the PCD.
Field Methods When You Lack A Gauge
The String Trick
On a five-lug wheel, run a string from one hole to the next-but-one hole around the circle to form a neat pentagon. Measure one side, then use any reputable PCD calculator to back into the circle. This won’t replace a shop gauge, yet it confirms if you’re near 110, 112, or 114.3.
Paper Template
Trace the bolt face on stiff paper, poke the centers, and measure across the template. Keep it flat and check twice. A template lets you test a wheel on a hub without lifting the car, which is handy when buying a used set.
When To Check Threads, Seat Style, And Torque
Stud diameter and thread pitch don’t change the PCD, yet they do affect hardware choice. Match seat style (conical, ball, or mag) and torque the nuts with a wrench to the maker’s spec. Re-torque after short mileage any time a wheel has been off. This routine pairs nicely with confirming hub rings are seated and center caps are tight.
Second Table: Quick Measurement Paths By Lug Count
| Lug Count | Where To Measure | Tip |
|---|---|---|
| 4 | Center-to-center straight across | Use a straight edge to align holes |
| 5 | Center of one hole to line across opposite gap | Confirm with a PCD gauge |
| 6 | Center-to-center straight across | Repeat to verify |
| 7 | Use a PCD ruler | Odd counts read best with a gauge |
| 8 | Center-to-center straight across | Check stud size too |
| 10 | Center-to-center straight across | Confirm both PCD and hardware |
Fitment Cross-Checks That Save Time
- Search by vehicle in a trusted fitment guide to confirm your measurement.
- Match center bore and seat type along with PCD.
- If using spacers, pick hub-centric parts and quality studs.
- Always tighten in a star pattern and use a torque wrench.
FAQ-Free Tips You Can Use Right Now
Snap a photo of the wheel face and jot the measurement on the photo. Keep a millimeter-only note on your phone to avoid mix-ups. If a used set lists only inch sizes, convert to metric and compare to your hub’s spec. When two sizes look close, measure again after rotating the wheel 72 degrees on five-lug to average out small errors. If you’re teaching a friend how to tell lug pattern on rims, show the five-lug trick first—confidence jumps fast once that step clicks.
How to Tell Lug Pattern on Rims When Buying Used Wheels
Ask the seller for the exact stamping on the back of the wheel: size, offset, and center bore. Bring a PCD ruler to the meet. If the rim uses conical seats and your car uses ball seats, plan the right nuts. Never force hardware to seat on the wrong profile. A short test fit on the vehicle, with one or two turns on each nut, confirms centering before you commit. Take a second to inspect for ovalized holes, cracked seats, or pulled threads on studs.
Troubleshooting Odd Readings
Reading drifts between 112 and 114.3: Use a gauge and re-check; five-lug tape reads can land between sizes. Even-lug wheel reads a hair short: You measured from edge to edge. Re-measure center to center. Numbers don’t match any table: Switch units and compare again; inch entries sometimes hide in metric lists and vice versa. Wheel won’t sit flush on test fit: Center bore is smaller than the hub or the seat style doesn’t match.
Safety Notes Before You Hit The Road
Once the wheels are on, torque to spec and re-check after 50–100 miles. Listen for clicks or feel for shake on the first drive. If you sense any wobble, stop and check lug seating and hub rings. A correct lug pattern with a wrong center bore can still feel rough. Never hammer lugs with an impact gun at full tilt; run the nuts snug by hand, then finish with a torque wrench.
Recap: Measuring Once, Confirming Twice
Count the lugs. Measure the right points for that count. Convert units cleanly. Match the reading to a standard size. Confirm with a gauge when the numbers sit close. With those steps, you’ll buy and mount with confidence and keep the ride smooth.