245/70R17
245/70R17 ships as an OEM size on the Ford F-150. At 30.50″ diameter with a 6.75″ sidewall (70% of section width), this size turns 661 revolutions per mile.
About 245/70R17
Factory fitments for 245/70R17 include the Ford F-150 — meaning replacement tires in this size see steady demand and broad brand availability. At 30.50″ overall diameter, 245/70R17 turns 661 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 70% aspect ratio gives it a tall, compliant sidewall that absorbs bumps well and protects rims off-road. The 17″ rim pairing is typical for light-truck, crossover, and mid-size SUV applications, so compatible wheels are easy to source new or used. Going one step shorter to 255/65R17 drops diameter by 1.48%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 245/75R17 adds 3.16% diameter — also inside the safe window, with marginally taller ride height. If you are shopping for a direct replacement, any tire within roughly ±0.7″ of the 30.50″ stock diameter (about ±2% in percentage terms) will keep ABS, TPMS, and odometer readings inside the vehicle's designed tolerance.
Compare with another size
275/65R18 or "33" for inch aliases245/70R17
- Diameter
- 30.5″ / 774.8mm
- Section Width
- 9.65″
- Sidewall
- 6.75″ / 171.5mm
- Circumference
- 95.83″
- Revs/Mile
- 661
225/70R17
- Diameter
- 29.4″ / 746.8mm
- Section Width
- 8.86″
- Sidewall
- 6.2″ / 157.5mm
- Circumference
- 92.37″
- Revs/Mile
- 686
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 57.83 mph (93.07 km/h). Your speedometer reads 3.61% high versus actual speed.