225/45R17 vs 265/65R18 Tire Comparison

225/45R17 has nominal diameter 24.9724 in; 265/65R18 has 31.5630 in. Diameter changes 26.391%; at indicated 60 mph the new nominal speed is 75.835 mph. Selected standard passenger and common truck/SUV tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.

225/45R17 vs 265/65R18 Tire Comparison reference last updated · reference source

Loading calculator…

Dated static reference; no live data is fetched. Verify current source values and assumptions before relying on results.

What this tool does

225/45R17 has nominal diameter 24.9724 in; 265/65R18 has 31.5630 in. Diameter changes 26.391%; at indicated 60 mph the new nominal speed is 75.835 mph. Selected standard passenger and common truck/SUV tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.

How to use the 225/45R17 vs 265/65R18 Tire Comparison

  1. Check Tire width (mm): 225.
  2. Check Tire aspect ratio (%): 45.
  3. Check Tire rim diameter (inches): 17.
  4. Check Tire B width (mm): 265.
  5. Check Tire B aspect ratio (%): 65.
  6. Check Tire B rim diameter (inches): 18.
  7. Check Indicated speed (mph): 60.
  8. Review the 225/45R17 vs 265/65R18 Tire Comparison result and its exact-value comparison table.
  9. Verify assumptions before applying the result.

Formula

difference%=(diameterB/diameterA−1)×100; actual speed=indicated speed×diameterB/diameterA
width
Tire width (mm)
aspect
Tire aspect ratio (%)
rim
Tire rim diameter (inches)
widthB
Tire B width (mm)
aspectB
Tire B aspect ratio (%)
rimB
Tire B rim diameter (inches)
speed
Indicated speed (mph)

Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.

Worked example

225/45R17 vs 265/65R18 Tire Comparison: Tire width (mm) = 225; Tire aspect ratio (%) = 45; Tire rim diameter (inches) = 17; Tire B width (mm) = 265; Tire B aspect ratio (%) = 65; Tire B rim diameter (inches) = 18; Indicated speed (mph) = 60. 225/45R17 has nominal diameter 24.9724 in; 265/65R18 has 31.5630 in. Diameter changes 26.391%; at indicated 60 mph the new nominal speed is 75.835 mph. Selected standard passenger and common truck/SUV tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.

Inputs

  • Tire width (mm)225
  • Tire aspect ratio (%)45
  • Tire rim diameter (inches)17
  • Tire B width (mm)265
  • Tire B aspect ratio (%)65
  • Tire B rim diameter (inches)18
  • Indicated speed (mph)60

Result

  • Diameter difference (%)26.39
  • Actual speed (mph)75.83
  • Ground clearance change3.3 in

225/45R17 versus 265/65R18

MeasurementOriginal tireNew tire
Diameter (in)24.9724409448818931.562992125984252
Sidewall (in)3.9862204724409456.781496062992126
Circumference (in)78.453237014645999.1580641883046
Revolutions/mile807.6148596414416638.9797997637102
Speed at indicated 30 mph3037.91738924798991
Speed at indicated 45 mph4556.87608387198487
Speed at indicated 60 mph6075.83477849597982
Speed at indicated 70 mph7088.47390824530979

Results explained

Diameter difference (%)
Diameter difference (%) from the formula above. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.
Actual speed (mph)
Actual speed (mph) from the formula above. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.
Ground clearance change
Ground clearance change from the formula above, expressed in in before metric conversion. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.

Frequently asked questions

Diameter difference is 6.5906 inches (26.391%).

3.9862 and 6.7815 inches respectively.

Nominal actual speed becomes 75.835 mph if calibrated to 225/45R17.

807.61 versus 638.98 geometric revolutions/mile.

This comparison cannot confirm fitment. Ground clearance changes 3.2952755905511815 in geometrically; verify wheel width, offsets, load/speed ratings and manufacturer requirements.