How this calculator works
US: gross range = available US gallons × miles per gallon. Metric: gross range = available liters ÷ liters per 100 km × 100. Usable range = gross range × (1 − reserve percent ÷ 100). Return-turnaround estimate = usable range ÷ 2.
Worked example
With 8 US gallons, 12 mpg, and a 25% reserve, gross range is 96 miles and usable range is 72 miles. The out-and-back turnaround estimate is 36 miles from your starting point.
Common questions
Should I use advertised economy?
Measured fuel use on similar rides is more useful. Start conservatively and update the estimate as you collect trip and refill data.
Are the results stored or sent anywhere?
No. Your entries are used in your browser for this calculation. Calculator entries are not saved. Optional My Machine and checklist preferences are stored locally as described in our privacy policy.
Start with fuel on board and comparable riding conditions
Enter the fuel available for the planned leg. Tank capacity is useful only when it reflects the fuel actually on board. Saving a machine may supply a published capacity; override it when the tank is partly full. Confirm your units: US gallons and mpg are different from liters and L/100 km.
Use measured economy from comparable rides instead of treating a catalog figure or one easy trip as a trail guarantee. Record distance and fuel used consistently. Mud, low-speed riding, elevation, load and route changes can make a future leg differ from your sample. The trail fuel and reserve guide explains how to build a conservative input.
The reserve is held back from the calculated gross range. The turnaround estimate divides usable range equally between outward and return travel; it does not model unequal terrain, detours or an alternate exit. Keep a route-specific contingency and reassess fuel during the trip. Use the pre-ride checklist to review fuel and trip equipment before leaving.