Aviation Training Experts

Aviation Training Experts™

Endurance Calculator

Calculate total flight endurance using usable fuel, fuel flow, and optional reserve fuel. This free aviation calculator helps pilots estimate time available in the air for planning and fuel management.

Calculate Endurance

Enter usable fuel, fuel flow, and optional reserve fuel to estimate total endurance and endurance after reserve.

Endurance Calculator

How It Works

Total Endurance:
Endurance = Usable Fuel ÷ Fuel Flow
Endurance After Reserve:
Endurance = (Usable Fuel - Reserve Fuel) ÷ Fuel Flow

This calculator estimates total time airborne based on the fuel available and the planned fuel flow.

What Is Endurance in Aviation?

Endurance is the amount of time an aircraft can remain airborne with the fuel available at a given fuel flow rate. It is one of the most important values in flight planning because it helps pilots estimate time available before fuel exhaustion.

Endurance is different from range. Range tells you how far the aircraft can travel, while endurance tells you how long it can stay in the air.

Why Pilots Use an Endurance Calculator

Endurance FAQ

What fuel should I use in the calculator?

Use usable fuel, not total fuel capacity, unless the total amount is all usable according to the aircraft documentation.

Why include reserve fuel?

Reserve fuel helps you understand how much time is truly available for the trip without relying on fuel that should remain untouched for legal or safety reasons.

What if fuel flow changes in flight?

Fuel flow may change with power setting, altitude, and mixture. This calculator is most accurate when you use a realistic fuel flow value for the part of flight you are planning.

Is this enough for dispatch or operational release planning?

This calculator is a planning aid. Always use your approved aircraft data, company procedures, POH, AFM, and regulatory reserve requirements where applicable.