Home · Calculators · Gears, Tires & Converter
Gear & Speed Table Calculator
See speed in every gear across your RPM range
A gear and speed table lists road speed at a chosen RPM in every gear, and the RPM the engine drops to after each upshift.
Formula: MPH per gear = RPM × tire ÷ (336.14 × axle × trans ratio) · RPM after shift = RPM × (next ratio ÷ current ratio)
What this number means
This builds a table of road speed versus RPM for each transmission gear, from your rear gear, gear ratios and tire diameter. It shows the whole pass at a glance — where each shift lands and what the stripe will look like in top gear.
What to change next
Use it to pick a rear gear that crosses the stripe at your target RPM and to spot a gear split that drops the engine out of its powerband. Recheck it after any tire or gear change, before blaming the engine for a lazy shift recovery.
Worked example
With a 4.10 rear gear, 28 in tire and 1.00 top gear, 6,500 RPM equals ≈ 132 MPH.
Related calculators
Read the guide: Gear Selection Guide →
Building a Jeep or 4x4 too? The same gear math drives your crawl ratio. RegearReady — our sister site — turns it into regear decisions: See the gear & speed table on RegearReady.