Nominal size comparison
245/70R16 vs 265/70R16
Diameter +3.74% · At indicated 60 mph: 62.24 mph estimated · Nominal radius change +14.0 mm
Calculated from nominal size labels. Instrument estimates assume unchanged calibration to the original size. Actual rolling circumference, clearance and tire specifications are not measured.
3–5% nominal diameter difference
The diameter difference is outside this calculator's ±3% comparison band. Estimated speed and distance changes are larger; fitment and calibration are not verified. Check vehicle and tire manufacturer specifications before fitting.
Visual diameter overlay
Installation still unverified
Diameter outside ±3%
- Diameter exceeds the ±3% comparison band; review vehicle-specific speedometer, ABS, and stability-control requirements.
- New tire is 20 mm wider; check inner strut clearance, fender clearance, and wheel offset.
- Check the vehicle placard and owner's manual for size and pressure, and confirm load and speed requirements with the vehicle and tire manufacturer. These are geometry estimates only.
Speedometer effect
When the vehicle's speedometer (calibrated to 245/70R16) reads 60 mph, the estimated speed with 265/70R16 mounted is:
Estimated speed change relative to indicated: +3.74% · Odometer reads low by 3.60% relative to actual distance. Per 100 actual miles, it records 96.40 miles (unchanged calibration).
Full comparison
| Measurement | 245/70R16 | 265/70R16 | Delta |
|---|---|---|---|
| Overall diameter | 29.50" | 30.61" | +3.74% |
| Section width | 245 mm | 265 mm | +20 mm |
| Sidewall height | 171.5 mm | 185.5 mm | +14.00 mm |
| Rim diameter | 16" | 16" | +0" |
| Circumference | 2354 mm | 2442 mm | +88 mm |
| Revs / mile | 684 | 659 | -25 |
| Nominal radius change | +14.0 mm | ||
Questions about this swap
What is the diameter difference between 245/70R16 and 265/70R16?
265/70R16 is 3.74% larger in overall diameter than 245/70R16 — a difference of 28.0 mm (1.10 inches).
How does 265/70R16 affect the speedometer if the car was calibrated for 245/70R16?
When the speedometer reads 60 mph (calibrated for 245/70R16), the estimated speed with 265/70R16 is 62.24 mph — an error of +3.74%.
Is it safe to replace 245/70R16 with 265/70R16?
3–5% nominal diameter difference. The diameter difference is outside this calculator's ±3% comparison band. Estimated speed and distance changes are larger; fitment and calibration are not verified. Check vehicle and tire manufacturer specifications before fitting.
All calculations use standard ETRTO formulas. Confirm fitment with a qualified tire professional and your vehicle's door-placard before purchasing.