TireGeoCalcMetric to Inches Tire Conversion Chart
Quick answer
Nominal geometryTable example: 205/55R16 → 205/55R16 · original-size calibration assumed
- 205/55R16 diameter
- 24.88in
- Diameter change
- 0.00%
- Actual at indicated 60 mph
- 60.00mph
Calculated from size markings. Not measured rolling dimensions or vehicle fitment approval.
Look up metric tire sizes as calculated inch dimensions in this conversion chart. The table emphasizes the result: overall diameter and section width beside each complete metric code. It includes passenger-car, SUV and pickup examples. For a worked explanation of how to convert an individual marking, use the separate step-by-step conversion guide linked below. These are nominal geometric calculations, not vehicle fitment approval. Check the vehicle manual and exact tire and wheel specifications, including load and speed ratings, approved rim width and clearance; consult the manual for any diameter change exceeding 3%.
Metric sizes converted to inches
Read the diameter and section-width columns separately: both use inches, but they measure different directions. The original metric marking identifies each row. Wheel diameter remains the number after R in that marking.
| Tire size | Diameter / height (mm) | Diameter / height (in) | Section width (in) | Sidewall (mm) | Circumference (mm) | Revolutions / mile |
|---|---|---|---|---|---|---|
| 205/55R16 | 631.9 | 24.88 | 8.07 | 112.8 | 1985.2 | 810.7 |
| 225/45R17 | 634.3 | 24.97 | 8.86 | 101.3 | 1992.7 | 807.6 |
| 195/65R15 | 634.5 | 24.98 | 7.68 | 126.8 | 1993.3 | 807.4 |
| 225/40R18 | 637.2 | 25.09 | 8.86 | 90.0 | 2001.8 | 803.9 |
| 215/55R16 | 642.9 | 25.31 | 8.46 | 118.3 | 2019.7 | 796.8 |
| 235/40R18 | 645.2 | 25.40 | 9.25 | 94.0 | 2027.0 | 794.0 |
| 205/60R16 | 652.4 | 25.69 | 8.07 | 123.0 | 2049.6 | 785.2 |
| 225/50R17 | 656.8 | 25.86 | 8.86 | 112.5 | 2063.4 | 779.9 |
| 215/60R16 | 664.4 | 26.16 | 8.46 | 129.0 | 2087.3 | 771.0 |
| 215/55R17 | 668.3 | 26.31 | 8.46 | 118.3 | 2099.5 | 766.5 |
| 235/45R18 | 668.7 | 26.33 | 9.25 | 105.8 | 2100.8 | 766.1 |
| 225/55R17 | 679.3 | 26.74 | 8.86 | 123.8 | 2134.1 | 754.1 |
| 235/50R18 | 692.2 | 27.25 | 9.25 | 117.5 | 2174.6 | 740.1 |
| 225/60R17 | 701.8 | 27.63 | 8.86 | 135.0 | 2204.8 | 729.9 |
| 245/45R19 | 703.1 | 27.68 | 9.65 | 110.3 | 2208.9 | 728.6 |
| 235/55R18 | 715.7 | 28.18 | 9.25 | 129.3 | 2248.4 | 715.8 |
| 225/65R17 | 724.3 | 28.52 | 8.86 | 146.3 | 2275.5 | 707.3 |
| 245/45R20 | 728.5 | 28.68 | 9.65 | 110.3 | 2288.7 | 703.2 |
| 235/65R17 | 737.3 | 29.03 | 9.25 | 152.8 | 2316.3 | 694.8 |
| 235/60R18 | 739.2 | 29.10 | 9.25 | 141.0 | 2322.3 | 693.0 |
| 245/65R17 | 750.3 | 29.54 | 9.65 | 159.3 | 2357.1 | 682.8 |
| 245/60R18 | 751.2 | 29.57 | 9.65 | 147.0 | 2360.0 | 681.9 |
| 245/75R16 | 773.9 | 30.47 | 9.65 | 183.8 | 2431.3 | 661.9 |
| 265/60R18 | 775.2 | 30.52 | 10.43 | 159.0 | 2435.4 | 660.8 |
| 255/55R20 | 788.5 | 31.04 | 10.04 | 140.3 | 2477.1 | 649.7 |
| 255/65R18 | 788.7 | 31.05 | 10.04 | 165.8 | 2477.8 | 649.5 |
| 265/65R18 | 801.7 | 31.56 | 10.43 | 172.3 | 2518.6 | 639.0 |
| 265/70R17 | 802.8 | 31.61 | 10.43 | 185.5 | 2522.1 | 638.1 |
| 265/75R16 | 803.9 | 31.65 | 10.43 | 198.8 | 2525.5 | 637.2 |
| 275/55R20 | 810.5 | 31.91 | 10.83 | 151.3 | 2546.3 | 632.0 |
| 285/70R17 | 830.8 | 32.71 | 11.22 | 199.5 | 2610.0 | 616.6 |
| 275/60R20 | 838.0 | 32.99 | 10.83 | 165.0 | 2632.7 | 611.3 |
| 315/70R17 | 872.8 | 34.36 | 12.40 | 220.5 | 2742.0 | 586.9 |
Nominal dimensions calculated from tire size markings; rounding is for display only.
- Tire size
- 205/55R16
- Diameter / height (mm)
- 631.9
- Diameter / height (in)
- 24.88
- Section width (in)
- 8.07
- Sidewall (mm)
- 112.8
- Circumference (mm)
- 1985.2
- Revolutions / mile
- 810.7
- Tire size
- 225/45R17
- Diameter / height (mm)
- 634.3
- Diameter / height (in)
- 24.97
- Section width (in)
- 8.86
- Sidewall (mm)
- 101.3
- Circumference (mm)
- 1992.7
- Revolutions / mile
- 807.6
- Tire size
- 195/65R15
- Diameter / height (mm)
- 634.5
- Diameter / height (in)
- 24.98
- Section width (in)
- 7.68
- Sidewall (mm)
- 126.8
- Circumference (mm)
- 1993.3
- Revolutions / mile
- 807.4
- Tire size
- 225/40R18
- Diameter / height (mm)
- 637.2
- Diameter / height (in)
- 25.09
- Section width (in)
- 8.86
- Sidewall (mm)
- 90.0
- Circumference (mm)
- 2001.8
- Revolutions / mile
- 803.9
- Tire size
- 215/55R16
- Diameter / height (mm)
- 642.9
- Diameter / height (in)
- 25.31
- Section width (in)
- 8.46
- Sidewall (mm)
- 118.3
- Circumference (mm)
- 2019.7
- Revolutions / mile
- 796.8
- Tire size
- 235/40R18
- Diameter / height (mm)
- 645.2
- Diameter / height (in)
- 25.40
- Section width (in)
- 9.25
- Sidewall (mm)
- 94.0
- Circumference (mm)
- 2027.0
- Revolutions / mile
- 794.0
- Tire size
- 205/60R16
- Diameter / height (mm)
- 652.4
- Diameter / height (in)
- 25.69
- Section width (in)
- 8.07
- Sidewall (mm)
- 123.0
- Circumference (mm)
- 2049.6
- Revolutions / mile
- 785.2
- Tire size
- 225/50R17
- Diameter / height (mm)
- 656.8
- Diameter / height (in)
- 25.86
- Section width (in)
- 8.86
- Sidewall (mm)
- 112.5
- Circumference (mm)
- 2063.4
- Revolutions / mile
- 779.9
- Tire size
- 215/60R16
- Diameter / height (mm)
- 664.4
- Diameter / height (in)
- 26.16
- Section width (in)
- 8.46
- Sidewall (mm)
- 129.0
- Circumference (mm)
- 2087.3
- Revolutions / mile
- 771.0
- Tire size
- 215/55R17
- Diameter / height (mm)
- 668.3
- Diameter / height (in)
- 26.31
- Section width (in)
- 8.46
- Sidewall (mm)
- 118.3
- Circumference (mm)
- 2099.5
- Revolutions / mile
- 766.5
- Tire size
- 235/45R18
- Diameter / height (mm)
- 668.7
- Diameter / height (in)
- 26.33
- Section width (in)
- 9.25
- Sidewall (mm)
- 105.8
- Circumference (mm)
- 2100.8
- Revolutions / mile
- 766.1
- Tire size
- 225/55R17
- Diameter / height (mm)
- 679.3
- Diameter / height (in)
- 26.74
- Section width (in)
- 8.86
- Sidewall (mm)
- 123.8
- Circumference (mm)
- 2134.1
- Revolutions / mile
- 754.1
- Tire size
- 235/50R18
- Diameter / height (mm)
- 692.2
- Diameter / height (in)
- 27.25
- Section width (in)
- 9.25
- Sidewall (mm)
- 117.5
- Circumference (mm)
- 2174.6
- Revolutions / mile
- 740.1
- Tire size
- 225/60R17
- Diameter / height (mm)
- 701.8
- Diameter / height (in)
- 27.63
- Section width (in)
- 8.86
- Sidewall (mm)
- 135.0
- Circumference (mm)
- 2204.8
- Revolutions / mile
- 729.9
- Tire size
- 245/45R19
- Diameter / height (mm)
- 703.1
- Diameter / height (in)
- 27.68
- Section width (in)
- 9.65
- Sidewall (mm)
- 110.3
- Circumference (mm)
- 2208.9
- Revolutions / mile
- 728.6
- Tire size
- 235/55R18
- Diameter / height (mm)
- 715.7
- Diameter / height (in)
- 28.18
- Section width (in)
- 9.25
- Sidewall (mm)
- 129.3
- Circumference (mm)
- 2248.4
- Revolutions / mile
- 715.8
- Tire size
- 225/65R17
- Diameter / height (mm)
- 724.3
- Diameter / height (in)
- 28.52
- Section width (in)
- 8.86
- Sidewall (mm)
- 146.3
- Circumference (mm)
- 2275.5
- Revolutions / mile
- 707.3
- Tire size
- 245/45R20
- Diameter / height (mm)
- 728.5
- Diameter / height (in)
- 28.68
- Section width (in)
- 9.65
- Sidewall (mm)
- 110.3
- Circumference (mm)
- 2288.7
- Revolutions / mile
- 703.2
- Tire size
- 235/65R17
- Diameter / height (mm)
- 737.3
- Diameter / height (in)
- 29.03
- Section width (in)
- 9.25
- Sidewall (mm)
- 152.8
- Circumference (mm)
- 2316.3
- Revolutions / mile
- 694.8
- Tire size
- 235/60R18
- Diameter / height (mm)
- 739.2
- Diameter / height (in)
- 29.10
- Section width (in)
- 9.25
- Sidewall (mm)
- 141.0
- Circumference (mm)
- 2322.3
- Revolutions / mile
- 693.0
- Tire size
- 245/65R17
- Diameter / height (mm)
- 750.3
- Diameter / height (in)
- 29.54
- Section width (in)
- 9.65
- Sidewall (mm)
- 159.3
- Circumference (mm)
- 2357.1
- Revolutions / mile
- 682.8
- Tire size
- 245/60R18
- Diameter / height (mm)
- 751.2
- Diameter / height (in)
- 29.57
- Section width (in)
- 9.65
- Sidewall (mm)
- 147.0
- Circumference (mm)
- 2360.0
- Revolutions / mile
- 681.9
- Tire size
- 245/75R16
- Diameter / height (mm)
- 773.9
- Diameter / height (in)
- 30.47
- Section width (in)
- 9.65
- Sidewall (mm)
- 183.8
- Circumference (mm)
- 2431.3
- Revolutions / mile
- 661.9
- Tire size
- 265/60R18
- Diameter / height (mm)
- 775.2
- Diameter / height (in)
- 30.52
- Section width (in)
- 10.43
- Sidewall (mm)
- 159.0
- Circumference (mm)
- 2435.4
- Revolutions / mile
- 660.8
- Tire size
- 255/55R20
- Diameter / height (mm)
- 788.5
- Diameter / height (in)
- 31.04
- Section width (in)
- 10.04
- Sidewall (mm)
- 140.3
- Circumference (mm)
- 2477.1
- Revolutions / mile
- 649.7
- Tire size
- 255/65R18
- Diameter / height (mm)
- 788.7
- Diameter / height (in)
- 31.05
- Section width (in)
- 10.04
- Sidewall (mm)
- 165.8
- Circumference (mm)
- 2477.8
- Revolutions / mile
- 649.5
- Tire size
- 265/65R18
- Diameter / height (mm)
- 801.7
- Diameter / height (in)
- 31.56
- Section width (in)
- 10.43
- Sidewall (mm)
- 172.3
- Circumference (mm)
- 2518.6
- Revolutions / mile
- 639.0
- Tire size
- 265/70R17
- Diameter / height (mm)
- 802.8
- Diameter / height (in)
- 31.61
- Section width (in)
- 10.43
- Sidewall (mm)
- 185.5
- Circumference (mm)
- 2522.1
- Revolutions / mile
- 638.1
- Tire size
- 265/75R16
- Diameter / height (mm)
- 803.9
- Diameter / height (in)
- 31.65
- Section width (in)
- 10.43
- Sidewall (mm)
- 198.8
- Circumference (mm)
- 2525.5
- Revolutions / mile
- 637.2
- Tire size
- 275/55R20
- Diameter / height (mm)
- 810.5
- Diameter / height (in)
- 31.91
- Section width (in)
- 10.83
- Sidewall (mm)
- 151.3
- Circumference (mm)
- 2546.3
- Revolutions / mile
- 632.0
- Tire size
- 285/70R17
- Diameter / height (mm)
- 830.8
- Diameter / height (in)
- 32.71
- Section width (in)
- 11.22
- Sidewall (mm)
- 199.5
- Circumference (mm)
- 2610.0
- Revolutions / mile
- 616.6
- Tire size
- 275/60R20
- Diameter / height (mm)
- 838.0
- Diameter / height (in)
- 32.99
- Section width (in)
- 10.83
- Sidewall (mm)
- 165.0
- Circumference (mm)
- 2632.7
- Revolutions / mile
- 611.3
- Tire size
- 315/70R17
- Diameter / height (mm)
- 872.8
- Diameter / height (in)
- 34.36
- Section width (in)
- 12.40
- Sidewall (mm)
- 220.5
- Circumference (mm)
- 2742.0
- Revolutions / mile
- 586.9
Use the two inch columns together
Find the complete metric code rather than looking up width alone. Read overall diameter in inches and section width in inches as separate dimensions. A wider tire can still be shorter if its aspect ratio or wheel diameter is lower. The table keeps both values visible because a single inch number cannot describe the whole tire.
Rows are ordered by calculated diameter, so adjacent entries are close in nominal height rather than alphabetic order. Width may move up or down between neighboring rows. Use the original metric code to distinguish them. The wheel diameter remains the final number after R, even when the calculated overall diameter is much larger.
Distinguish inch dimensions from flotation markings
A flotation marking gives overall diameter, section width and wheel diameter in inches. Converted dimensions alone do not identify an interchangeable catalog product.
Keep units and precision consistent
One inch equals exactly 25.4 millimeters, and the chart retains full precision until display. Use the millimeter diameter column for further calculations because converting a rounded inch value back can introduce a small discrepancy.
Choose the right next comparison
If you want to learn the conversion procedure, follow the linked metric-to-inches tutorial instead of copying rounded values from this lookup table. If you want to compare replacements, enter the original and proposed complete sizes in the calculator. A chart lookup answers a unit question; a pair comparison answers a difference question.
Check an inch result against its metric row
For 205/55R16, the nominal diameter is 631.9 mm. Dividing by 25.4 gives 24.88 inches after display rounding. Its 205 mm section width converts to 8.07 inches. Neither inch figure changes the 16-inch wheel requirement: overall diameter includes the wheel and both sidewalls, while section width runs across the assembly.
A 265/70R17 has a calculated diameter of 802.8 mm, or 31.61 inches, and a section width of 10.43 inches. A 275/55R20 is wider at 10.83 inches and slightly taller at 31.91 inches. The larger wheel does not add three inches to overall height because the sidewalls are shorter.
Use the section-width column for a width conversion and the diameter column for a height conversion. For example, entering 225 divided by 25.4 converts only the first number of a 225-width code. It cannot give overall tire height without the aspect ratio and wheel diameter. Record the complete marking with any copied result so the two dimensions remain identifiable.
Frequently asked questions
How does this chart differ from the conversion guide?
This chart is a lookup for 33 complete sizes, ordered by calculated overall diameter. The guide at /tire-guides/how-to-convert-metric-tire-size-to-inches/ explains the formula step by step for an individual size, including how width, aspect ratio and wheel diameter contribute to the result.
Why does section width differ from tread width?
Section width describes the nominal width across the sidewalls. Tread width describes a different part of the tire and depends on product design.
Where is the conversion method explained?
The linked metric-to-inches guide walks through the method. This page concentrates on a larger lookup table so you can compare several complete sizes quickly without repeating that tutorial.
Continue your comparison
These are nominal geometric calculations, not vehicle fitment approval. Check the vehicle manual and exact tire and wheel specifications, including load and speed ratings, approved rim width and clearance; consult the manual for any diameter change exceeding 3%.
Reference tables: Load index chart and Speed rating chart.