Nominal vs Published Dimensions Comparator
Compare a tire's nominal size-code dimensions with the manufacturer's published diameter, width and revolutions for one exact model.
Compare estimates with manufacturer specifications.
Nominal vs Published Dimensions Comparator: Tire Size Inputs
Compare two tire sizes here. Use the formulas and reference tables below for this tool's specific calculation.
How Nominal vs Published Dimensions Comparator Works?
The Nominal vs Published Dimensions Comparator shows size-code estimates beside the tire maker's published measurements. It first calculates the nominal dimensions. It then places the published figures next to them so you can see each gap. Follow the 4 steps below.
Enter the size code
Type the size, for example 265/70 R17, to generate nominal width, diameter and revs per mile.
Enter published figures
Copy overall diameter, section width and revs per mile from the tire maker's spec sheet.
Note the measuring rim
Enter the measuring rim width listed in the spec sheet.
Read the gaps
The comparator shows the gap for each dimension in mm, inches and percent.
Nominal vs Published Dimensions Comparator Formula
The Nominal vs Published Dimensions Comparator formula is Gap% = (Published − Nominal) ÷ Nominal × 100 for each dimension.
ΔOD = OD_pub − OD_nomΔW = W_pub − W_nomGap% = Δ ÷ Nominal × 100- OD_nom
- Diameter from the size code (mm)
- OD_pub
- Diameter from the tire maker's sheet (mm)
- W_pub
- Published section width on the measuring rim (mm)
Worked example
A 265/70 R17 tire has a nominal diameter of 802.8 mm (31.61 in). A spec sheet lists 798 mm (31.4 in). The gap is −4.8 mm (−0.19 in), or −0.60%.
Nominal vs Published Dimensions Comparator Conversion Table
The Nominal vs Published Dimensions Comparator conversion table compares nominal and typical published diameter and width for 5 sizes.
| Size | Nominal diameter | Published diameter | Diameter gap | Width nominal / published |
|---|---|---|---|---|
| 225/45 R17 | 634.3 mm | 632 mm | -2.3 mm (-0.36%) | 225 / 229 mm |
| 265/70 R17 | 802.8 mm | 798 mm | -4.8 mm (-0.60%) | 265 / 272 mm |
| 245/40 R18 | 653.2 mm | 652 mm | -1.2 mm (-0.18%) | 245 / 248 mm |
| 205/55 R16 | 631.9 mm | 632 mm | +0.1 mm (+0.02%) | 205 / 214 mm |
| 275/55 R20 | 810.5 mm | 808 mm | -2.5 mm (-0.31%) | 275 / 282 mm |
Published values in the table are representative. Each model's published values come from that model's data sheet.
What is Nominal vs Published Dimensions Comparator?
A Nominal vs Published Dimensions Comparator is a tool that shows how far a specific tire model's real dimensions sit from the theoretical dimensions of its size code. Nominal values come from arithmetic. Published values come from measurements of the actual product.
ISO and TRA standards allow a new tire's measured section width to exceed nominal width by up to 4% to 6% and overall diameter to vary by about ±3%.
Tight-clearance builds, AWD vehicles and speedometer calibration benefit from published dimensions over nominal ones.
What are the uses of Nominal vs Published Dimensions Comparator?
There are 4 main uses of the Nominal vs Published Dimensions Comparator, including clearance planning and model selection.
Clearance planning
Use the larger published width when space is tight.
Model selection
Pick the model closest to the stock tire's true diameter.
Data checking
Spot errors on retailer listings that copy nominal values.
Calibration accuracy
Base speedometer corrections on published figures.
Related Core Tire Dimensions Tools
View All 134 Subtools →Compare two tire sizes.
Compare several sizes together.
Estimate nominal overall diameter.
Calculate absolute and percentage differences.
Estimate nominal circumference.
Compare estimated rolling distances.