Fuel Tank Volume Calculator
Calculate heating oil, diesel, and gasoline tank gallons from dipstick depth. Sized for standard 275 & 330 gallon basement and skid tanks.
In a horizontal cylinder, fluid volume is non-linear with dipstick height. The circular cross section requires exact geometric segment integration.
Multiplying the filled liquid cross-section by the length gives the current held volume.
Calculates held gallons and remaining capacity for standard oval, horizontal cylinder, and rectangular heating oil and diesel tanks. A standard 275-gallon oval basement oil tank (27" × 44" × 60") with a 13-inch dipstick reading holds approximately 130 gallons (47% full).
Fuel Tank Volume Calculator Formula & Sizing Rules
| Variable | Definition | Standard Units |
|---|---|---|
| Gallons | US liquid gallons of fuel oil | gal |
| Dipstick | Inches of fuel measured from bottom of tank | inches |
Standard Residential Heating Oil Tank Dimensions
Most residential oil tanks in North America are either 275 gallons or 330 gallons with an oval cross-section. Because of the curved sides and rounded bottom, fuel volume does not increase linearly with stick depth. Sizing with our calibrated dipstick model prevents running out of fuel in winter.
Common Project Sizing Mistakes
- Assuming heating oil weighs 8.34 lbs like water (fuel oil is lighter, approx 7.1 lbs/gal)
- Forgetting that oil tanks should never be filled to 100% capacity to allow for vapor space and thermal expansion
Frequently Asked Questions
How do you read a fuel oil tank dipstick?▼
What is the usable capacity of a 275-gallon oil tank?▼
How many gallons are in an oval heating oil tank per inch of stick depth?▼
How do you calculate diesel fuel volume in a cylindrical skid tank?▼
Authoritative Sources & Reference Standards
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811 — National Institute of Standards and Technology (NIST). Verified 2026-10-01.
Official SI unit definitions, conversion factors (Appendix B), and precision standards for cubic meters, liters, and US customary units.
- NIST Handbook 44: Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices — NIST Office of Weights and Measures. Verified 2026-10-01.
Legal commercial measurement standards for liquids, tanks, and bulk volumetric containers in the United States.