How much reserve fuel is required for VFR flight?

Under FAA regulations (14 CFR 91.151), VFR flights during the day require enough fuel to fly to the first point of intended landing plus 30 minutes at normal cruising speed. For VFR night flights, the reserve requirement increases to 45 minutes. EASA regulations (NCO.OP.125) similarly require 30 minutes reserve for VFR flights.

What is the fuel flow rate for a Cessna 172?

A Cessna 172 typically burns between 8-10 gallons per hour (GPH) at cruise power settings. The exact fuel flow depends on the model: 172N burns about 8.5 GPH, 172S burns about 8.8 GPH, and 172R burns about 7.5 GPH due to fuel injection. Always verify with your specific aircraft's POH.

How do I calculate fuel required for a flight?

Calculate fuel required using: Flight Time (hours) × Fuel Flow (GPH) = Trip Fuel. Then add: Alternate fuel (if applicable), Reserve fuel (30-45 minutes minimum), and Taxi/climb fuel (typically 1-3 gallons). Total fuel = Trip + Alternate + Reserve + Taxi/Climb. Always round up and add a safety margin.

What is the difference between range and endurance?

Range is the maximum distance an aircraft can fly with available fuel, measured in nautical miles. Endurance is the maximum time an aircraft can remain airborne with available fuel, measured in hours and minutes. Maximum range occurs at best range speed; maximum endurance occurs at minimum power required (slower than best range speed).

How does altitude affect fuel consumption?

At higher altitudes, engines produce less power due to thinner air, but true airspeed increases for the same indicated airspeed. The net effect typically improves fuel efficiency at higher altitudes. However, climbing to altitude consumes extra fuel. For trips under 200NM, staying lower may be more efficient; for longer trips, higher altitudes generally save fuel.

How much does headwind affect fuel consumption?

Headwinds increase fuel consumption by extending flight time. For example, a 20-knot headwind on a 200NM flight at 120 knots ground speed increases flight time by 20% (from 1.5 hours to 1.8 hours), consuming 20% more fuel. Conversely, tailwinds reduce fuel consumption proportionally. Always factor winds into your fuel calculations.

Fuel Consumption Calculator - Aviation Flight Planning

Fuel Planning Calculator

Aircraft & Fuel Information

Fuel Flow Rate

Cruise fuel consumption rate

Fuel Capacity

Total usable fuel capacity

True Airspeed

Cruise speed in knots

Current Fuel On Board

Flight Planning

Flight Distance

Nautical miles

Alternate Distance

Distance to alternate (NM)

Reserve Minutes

Additional reserve fuel

Performance Factors (Optional)

Headwind Component

Knots (positive for headwind)

Fuel Flow Factor

Multiplier (1.0 = normal)

Taxi/Climb Fuel

Fuel Calculations

Total Fuel Required

Including all reserves

Trip Fuel

Alternate Fuel

Reserve Fuel

Taxi/Climb Fuel

Maximum Range

With current fuel

Maximum Endurance

With current fuel

Fuel Planning Guidelines

VFR Requirements

Day: 30 minutes reserve
Night: 45 minutes reserve
Plus alternate if required

IFR Requirements

45 minutes reserve minimum
Alternate airport fuel
Contingency fuel recommended

Safety Factors

Consider weather diversions
Account for climb/approach fuel
Plan for traffic delays

Aircraft Fuel Flow Reference Table

Typical fuel consumption rates for popular general aviation aircraft at cruise power settings.

Aircraft Type	Engine	Fuel Flow (GPH)	Fuel Flow (L/h)	Cruise TAS	Range (NM)
Cessna 150/152	O-200 / O-235	5.5 - 6.5	21 - 25	95-105 kts	350-450
Cessna 172 Skyhawk	O-320 / IO-360	8.0 - 10.0	30 - 38	110-125 kts	500-640
Cessna 182 Skylane	O-470 / IO-540	12.0 - 14.0	45 - 53	130-145 kts	820-1000
Piper Cherokee 140	O-320	7.5 - 9.0	28 - 34	110-120 kts	500-600
Piper Arrow	IO-360	10.0 - 13.0	38 - 49	135-150 kts	700-900
Beechcraft Bonanza	IO-520 / IO-550	13.0 - 16.0	49 - 61	160-175 kts	850-1100
Cirrus SR22	IO-550-N	15.0 - 18.0	57 - 68	175-185 kts	900-1200
Diamond DA40	IO-360	9.0 - 11.0	34 - 42	135-145 kts	700-850

Important: These are approximate values for planning purposes. Actual fuel consumption varies with altitude, temperature, leaning technique, and aircraft condition. Always consult your specific aircraft's POH for accurate fuel flow data.

Aviation Fuel Types & Properties

100LL (Avgas)

Density: 6.0 lbs/gal
Density: 0.72 kg/L
Color: Blue
Use: Piston engines

Jet-A / Jet-A1

Density: 6.8 lbs/gal
Density: 0.81 kg/L
Color: Clear/Straw
Use: Turbine engines

MoGas (Auto Fuel)

Density: 5.8-6.0 lbs/gal
Density: 0.70-0.72 kg/L
Color: Various
Use: STC required

UL94 (Unleaded)

Density: 6.0 lbs/gal
Density: 0.72 kg/L
Color: Clear
Use: Low compression

Fuel Conversion Quick Reference

1 US Gallon

= 3.785 Liters

1 Imperial Gallon

= 4.546 Liters

1 Liter 100LL

= 1.59 lbs (0.72 kg)

1 Gallon 100LL

= 6.0 lbs (2.72 kg)

Fuel Planning Regulatory Requirements

FAA Requirements (United States)

14 CFR 91.151 - VFR Fuel Requirements

Day VFR flights must carry enough fuel to fly to the first point of intended landing and, assuming normal cruising speed, to fly after that for at least 30 minutes.

14 CFR 91.153 - IFR Fuel Requirements

IFR flights must carry sufficient fuel to complete the flight to the first airport of intended landing, fly from that airport to the alternate (if required), and fly after that for 45 minutes at normal cruising speed.

14 CFR 91.167 - IFR Alternate Requirements

Specifies when alternate airports are required and affects fuel planning calculations for extended IFR operations.

AC 91-74B - Pilot Guide to Flight Planning

Provides comprehensive guidance on fuel planning methodologies, emphasizing conservative fuel calculations and contingency planning.

EASA Requirements (Europe)

SERA.5005(f) - Pre-flight Action

Commanders must determine that the aircraft carries sufficient fuel for the planned operation, plus reserves for contingencies and alternate aerodromes.

NCO.OP.125 - Fuel Requirements VFR

VFR flights must carry sufficient fuel for the planned flight plus 30 minutes at normal cruising consumption, or to the nearest suitable aerodrome plus 30 minutes.

NCO.OP.130 - Fuel Requirements IFR

IFR flights must carry fuel for the destination plus alternate aerodrome (when required) plus final reserve of 45 minutes at holding speed.

Critical Fuel Planning Safety

Legal Minimums vs. Safe Practices

Regulatory minimums are absolute legal requirements. Professional pilots typically carry additional fuel beyond minimums to account for weather changes, traffic delays, and operational contingencies.

Fuel Exhaustion Statistics

Fuel-related accidents remain a leading cause of aviation incidents. Many occur when pilots operate at or near regulatory minimums without additional safety margins.

Weather Impact

Headwinds, altitude changes, and route deviations can significantly increase fuel consumption beyond planned amounts. Always plan for meteorological contingencies.

Professional Best Practices

Conservative Planning

Use higher fuel flow rates than published
Plan for headwinds and weather delays
Add extra fuel for training flights
Consider airport fuel availability

En Route Monitoring

Monitor actual vs. planned fuel burn
Calculate revised arrival fuel regularly
Identify diversion points with fuel
Reassess weather impact continuously

Risk Management

Establish personal fuel minimums above legal
Plan multiple fuel stops for long flights
Consider weight-fuel trade-offs
Brief passengers on fuel considerations

Related Aviation Calculators

Complete your flight planning with these professional aviation tools:

Crosswind Calculator

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Density Altitude Calculator

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True Airspeed Calculator

Convert indicated airspeed to true airspeed at altitude

Distance & Bearing Calculator

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Performance Calculator

Calculate takeoff and landing distances with safety margins

Weight & Balance Calculator

Calculate center of gravity and verify CG envelope limits

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