Work out payload range tradeoff instantly with clear inputs, formula shown and shareable results.
Every kilogram of payload is a kilogram of fuel you cannot carry once the aircraft is at maximum take-off weight. Fuel available equals MTOW minus empty weight minus payload, and range is that fuel multiplied by specific air range, giving the classic payload-range trade curve.
Payload-range
Fuel = MTOW - OEW - payload; Range = fuel x specific air range
Aviation results are planning estimates only. Always verify take-off, landing, fuel, weight and balance figures against the certified Aircraft Flight Manual, current performance charts and applicable aviation regulations before flight.
Below MTOW the aircraft is volume or structurally limited so range grows with fuel at constant payload; once at MTOW every extra litre must displace payload, so the curve slopes down.
Nautical miles flown per unit of fuel burnt. It varies with weight and altitude, so use a cruise-average figure for planning.