Fuel Per Navigation Leg Calculator
Calculate fuel needed for each leg of a multi-stop journey in nautical miles or km.
Plan fuel stops for sailing, boating, or long-distance driving routes.
How Fuel Per Navigation Leg Is Calculated
Marine and aviation navigation breaks a journey into legs — segments between waypoints. Calculating fuel burn per leg ensures you arrive with sufficient reserve.
Fuel Per Leg Formula:
Fuel (L) = (Distance nm or km) / Speed × Burn Rate (L/hr)
Or equivalently:
Fuel (L) = Distance / (Speed × Fuel Economy L/nm)
Aviation Example (Cessna 172):
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Fuel burn: ~32 liters/hour (8.5 US gal/hr)
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Cruise speed: 200 km/h (108 knots)
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Leg distance: 350 km (189 nm)
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Time = 350 / 200 = 1.75 hours
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Fuel = 1.75 × 32 = 56 liters
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Reserve required (FAA VFR): 45 min = 0.75 hr × 32 = 24 liters
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Total needed: 56 + 24 = 80 liters (Cessna 172 holds ~204L — ample)
Marine Example (40 ft sailboat with auxiliary diesel):
- Fuel burn: 4 liters/hour at 7 knots motoring
- Leg: 45 nautical miles
- Time = 45 / 7 = 6.43 hours
- Fuel = 6.43 × 4 = 25.7 liters
- Add 15% reserve: 29.5 liters
Reserve Rules:
- Aviation VFR day: 30 min (45 min recommended)
- Aviation IFR: 45 min at alternate
- Offshore sailing: carry 200% of calculated motoring fuel
Fuel Density: Aviation fuel (Avgas 100LL): 0.72 kg/L. Diesel: 0.85 kg/L. Weight affects aircraft weight and balance calculations.