Fuel Calculator
How much fuel will you actually burn on this trip — accounting for the fact that loaded off-road MPG is nothing like the highway figure on your window sticker.
Your trip
Use your loaded / off-road MPG, not your highway figure. Off-road consumption typically runs 30–50% worse.
Fuel you'll carry beyond the main tank. Leave at 0 if none.
Buffer kept in reserve for detours, recovery, idling. 25% is a common backcountry default.
Your fuel plan
Fuel needed (with reserve)
52.1 gal
2 refuels needed — you'd be 31.1 gal short otherwise.
- Total distance
- 500 mi
- Fuel needed (no reserve)
- 41.7 gal
- Range, main tank
- 252 mi
- Range, main + aux
- — no aux
- Total capacity
- 21 gal
- Reserve buffer
- 10.4 gal
Estimates only. Real-world MPG varies with elevation, terrain, load, tire pressure, and driver. Always verify fuel availability before committing to a remote leg.
Notes on the math
- Distance × 2 for round-trip.The toggle assumes you're planning a there-and-back; uncheck it for one-way or point-to-point loops where you've already added the return leg.
- Use loaded off-road MPG, not highway.A rig loaded with gear and fluids on dirt typically returns 30–50% worse than the same vehicle empty on pavement. If you don't know yours yet, track a tank or two on a real trip.
- The reserve buffer is non-negotiable.Detours, recovery, idling at camp with the heater on, and the fact that fuel gauges lie all eat into your margin. 25% is a common backcountry default; 33% if you're truly remote.
- Refuel count. Assumes you can fill main + aux to full at each stop. Plan stops against actual gas-station locations, not just total mileage.
Background reading on the formulas, jerry-can sizing, and how to carry aux fuel safely: Overland fuel storage.