Climb & Descent Fuel Budget Calculator
Price the climb's gluttony and the descent's frugality separately — the segment fuel budget that flat cruise-only planning silently misses.
On typical profiles the climb's surplus and descent's discount nearly cancel — the flat method's secret. They stop canceling on short flights with big climbs, where the climb can be a third of the whole burn: exactly when fuel is tightest.
Formula
⚠️ For flight planning and education only — verify with official sources, your POH/AFM and certified equipment. Not for primary navigation.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Price the climb's gluttony and the descent's frugality separately — the segment fuel budget that flat cruise-only planning silently misses.
About Climb & Descent Fuel Budget Calculator
Cruise-flow-times-total-time is the planning shortcut everyone uses, and it survives on a hidden cancellation: the climb burns 40% over cruise while the descent burns 35% under, and on a long flight they wash. This calculator does the three-segment budget explicitly — climb, cruise, descent, each at its own flow — and reports both the honest total and the flat method's error, which balloons exactly where margins are thinnest: short hops to high altitudes.
How to use Climb & Descent Fuel Budget Calculator
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula total = Σ(segment time × segment flow); vs flat = total time × cruise flow substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Climb & Descent Fuel Budget Calculator?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula total = Σ(segment time × segment flow); vs flat = total time × cruise flow with sources cited on the page
- ✓On typical profiles the climb's surplus and descent's discount nearly cancel — the flat method's secret. They stop canceling on short flights with big climbs, where the climb can be a third of the whole burn: exactly when fuel is tightest.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
When does the flat method genuinely fail?+
Short flights with proportionally long climbs: a 45-minute hop climbing to 10,500 ft spends a third of its time at climb flow, and the flat estimate runs a gallon or more short — against tanks that were light to begin with. Mountain-airport departures, training flights with multiple climbs, and turbocharged aircraft cruising high are the repeat offenders.
Why does the climb burn so much more per hour?+
Full throttle and full rich: maximum power demands maximum flow, and the full-rich mixture (cooling protection at high power) adds 15–20% on top of what the power alone needs. A trainer cruising leaned at 9.5 gph can gulp 14+ in the climb — the POH's time-fuel-distance-to-climb table is this reality in tabular form.
Is the descent discount safe to count on?+
Mostly: a planned cruise descent at low power, leaned, genuinely sips (60–70% of cruise flow). The discount evaporates with slam-dunk arrivals (power back up for level-offs), turbine-style step descents, or carb-ice paranoia keeping power high. Budget the discount when you control the profile; surrender it in busy terminal airspace.
How do I get my aircraft's segment flows?+
Climb: POH climb-fuel table, or your fuel totalizer's reading during a steady Vy climb. Descent: totalizer again at your standard descent power. No totalizer? Bracket from the POH cruise table's lowest line for descent and the climb table for climb — then validate the whole profile against actual fuel added over a dozen flights, the ultimate audit this calculator's inputs deserve.
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