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.
Can I use fire-road economy for a technical trail?
Do not assume it transfers. Use records from comparable terrain and load, test more conservative assumptions, and keep a route-specific reserve and return plan.
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.
Reading this estimate
Fuel aboard multiplied by assumed economy gives gross range. Holding your reserve aside reduces planned range, and dividing by two estimates an equal outward and return trip. Unequal terrain, idling and detours need a route-specific plan beyond that division.
Is tank capacity the same as fuel aboard?
No. A partly filled tank contains less than published capacity. Override a machine default with the fuel actually available for the planned leg.
Does a turnaround figure cover a harder return climb?
Not automatically. Equal division assumes comparable consumption. Budget each leg separately when terrain or operating conditions differ.
Supporting explanation reviewed October 8, 2026.