Fuel volume and weight
Converts fuel between volume and weight using a density you choose or a nominal fuel type.
A published result changed on 2026-09-23: Promoting these two tools to stable removed EXPERIMENTAL_TOOL from their warnings, which moved NOMINAL_VALUE_USED and UNIT_ASSUMED from index 1 to index 0 and broke the two vectors that pinned the index. Nothing computed changed. v001 is superseded by v021 and v002 by v025, both naming the warning by its code with the meta.warnings.*.code form the runner supports, so no warning sorting above them can shift them again -- the same fix geometry.validity.make-valid v001 took for the same reason. Changelog
50 US gal of fuel weighs 300 lb at 6 lb/US gal.
- 6 lb/US gal is a nominal planning density for avgas 100LL. Use a measured density for weight and balance.
- Volume
- Density used
Provenance
- Computed by
- units.fuel.convert 1.0.0, core 0.1.0
- Model
- mass = volume × density
- Accuracy
- Exact for a given density. Nominal fuel densities vary about ±3% with temperature and batch
- Notes
- 1 shown with the answer
- Cites
- National Institute of Standards and Technology, Guide for the Use of the International System of Units (SI), NIST Special Publication 811; Federal Aviation Administration, Pilot's Handbook of Aeronautical Knowledge, FAA-H-8083-25C
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: mass = volume × density
Accuracy: Exact for a given density. Nominal fuel densities vary about ±3% with temperature and batch
When to use this: Use this to turn fuel on board into weight, or a weight allowance into gallons or litres: a load sheet, a weight-and-balance line, a tankering decision. Give it a measured density when you have one; give it a fuel type and it uses the published nominal figure and tells you it did.
Limitations: A nominal density is a planning number, not a measurement. Fuel density moves with temperature and batch by roughly 3%, and Jet A at 6.7 lb per US gallon is quoted at 15 °C, so on a hot day the same gallons weigh less; for weight and balance, use a measured density. The gallon is the US liquid gallon throughout, not the imperial one. And nothing here knows about usable versus unusable fuel, tank geometry or what is already burnt: it converts the quantity you give it.
Worked example: 50 US gallons of avgas in pounds. Source: FAA-H-8083-25C Chapter 10 (6 lb/gal). It is golden test vector v021, and every build checks the tool still gives its answer within its tolerance.
You enter
- Fuel type
- avgas-100ll
- Volume
- 50 galUS
You get
- Weight
- 300 lb
- Volume
- 50 US gal
- Density used
- 6 lb/US gal
Review: Not yet independently reviewed by a metrologist.
Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Changes
- 2026-09-23, result change: Promoting these two tools to stable removed EXPERIMENTAL_TOOL from their warnings, which moved NOMINAL_VALUE_USED and UNIT_ASSUMED from index 1 to index 0 and broke the two vectors that pinned the index. Nothing computed changed. v001 is superseded by v021 and v002 by v025, both naming the warning by its code with the meta.warnings.*.code form the runner supports, so no warning sorting above them can shift them again -- the same fix geometry.validity.make-valid v001 took for the same reason. Changelog
Checked against: 20 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, National Institute of Standards and Technology, 2008 edition. Appendix B.8, Factors for units listed alphabetically.
- Pilot's Handbook of Aeronautical Knowledge, FAA-H-8083-25C, Federal Aviation Administration, FAA-H-8083-25C. Chapter 10, Weight and Balance (avgas 6 lb/gal, jet fuel 6.7 lb/gal).