Fuel Howgozit Calculator (Progress vs Plan)
The continuous version of PNR thinking: at any checkpoint, fuel-used vs distance-made against plan — the drift that predicts a problem hours before the gauge does.
Airlines call the plotted version a howgozit. The power is in the trend: one bad checkpoint is wind or sloppy leaning; two establishes a rate; projecting that rate to destination converts 'feels fine' into a number that argues back.
Formula
⚠️ For flight planning and education only — verify with your POH/AFM and official sources. Not for primary navigation or in-flight emergency decision-making without POH data.
The continuous version of PNR thinking: at any checkpoint, fuel-used vs distance-made against plan — the drift that predicts a problem hours before the gauge does.
About Fuel Howgozit Calculator (Progress vs Plan)
Fuel exhaustion accidents share a script: the plan was fine, the deviations were each small, and nobody multiplied them out until the options were gone. The howgozit — aviation's oldest progress chart — breaks the script: at each checkpoint, compare fuel-per-mile actual against plan, project the actual rate to destination, and let the arithmetic argue with optimism. This calculator runs one checkpoint of it; the discipline is running every checkpoint.
How to use Fuel Howgozit Calculator (Progress vs Plan)
- 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 score = planned gal/nm ÷ actual gal/nm; projection = actual rate × full distance substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Fuel Howgozit Calculator (Progress vs Plan)?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula score = planned gal/nm ÷ actual gal/nm; projection = actual rate × full distance with sources cited on the page
- ✓Airlines call the plotted version a howgozit. The power is in the trend: one bad checkpoint is wind or sloppy leaning; two establishes a rate; projecting that rate to destination converts 'feels fine' into a number that argues back.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
What does a fuel score below 1.0 actually tell me?+
That each mile is costing more fuel than planned — from stronger headwinds, richer-than-planned mixture, lower-than-planned altitude, or (the reason the check exists) something wrong: a stuck-rich cylinder, a cap venting fuel, a leak. The score doesn't diagnose; it detects, early. Diagnosis starts at the second consecutive bad checkpoint.
How is this better than glancing at the gauges?+
Gauges report state with ±10% honesty; the howgozit reports RATE against plan with dipstick-and-clock accuracy — and rate is what predicts. A gauge showing half tanks 'feels fine' whether you're on plan or trending 20% over; the projection column knows the difference 200 miles before the gauge does. Airlines plot it leg-long for exactly this reason.
What actions does a bad trend justify, in order?+
Cheap to expensive: verify leaning (the most common fix — proper peak-finding recovers 1–2 gph), confirm altitude/power against plan, recompute wind (climb or descend if the forecast lied), then insert the fuel stop EARLY — a 25-minute stop chosen at cruise beats the same stop chosen during descent with the low-fuel light arguing. The projection's whole value is making the early choice visible.
How do airlines formalize this?+
A plotted line of fuel-remaining vs distance, drawn at planning with required-reserve floors marked, updated by ACARS or crew at each waypoint: deviations show as the actual line diverging from plan, and company SOPs trigger at defined gaps. The GA translation is a navlog column — planned-fuel-remaining per checkpoint, filled against the totalizer or clock — which is precisely the arithmetic this page automates.
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