Heating oil tank size chart & capacity calculator

Most home heating-oil tanks come in a handful of standard sizes — 275 gallons being by far the most common above ground, with 550- and 1,000-gallon cylinders typical underground. Use the chart for standard dimensions, or the calculator to estimate capacity from measurements and how much oil is left from your gauge reading.

Standard heating oil tank sizes

TankTypical dimensionsWhere usedUsable fill (~90%)
275 gal vertical oval27" W × 44" H × 60" LBasement/garage — the standard~250 gal
275 gal horizontal oval44" W × 27" H × 60" LBasement, low-clearance~250 gal
330 gal oval27" W × 44" H × 72" LLarger homes, aboveground~300 gal
550 gal cylinder48" Ø × 65" LUnderground~500 gal
1,000 gal cylinder48" Ø × 130" LUnderground~900 gal

Dimensions are the common manufacturer standards — individual tanks vary slightly.

How much oil is left?

Frequently asked questions

What size is a normal home heating oil tank?

The standard aboveground residential tank is a 275-gallon oval (roughly 27" wide, 44" high, 60" long), installed vertically or horizontally; 330-gallon ovals are the longer variant. Buried residential tanks are usually 550- or 1,000-gallon steel cylinders. Dimensions vary slightly by manufacturer.

How much oil is actually in a "full" 275-gallon tank?

Less than 275 gallons — fills are typically stopped around 250 gallons (about 90%) to leave air space for expansion. Your gauge reading times usable capacity gives a realistic estimate, which is what the calculator does.

Why does tank size matter when buying a home with oil heat?

An underground tank of any size is a liability question in NJ real estate: buried residential heating-oil tanks are common at older homes, and a leaking one can mean a five-figure cleanup. If you’re buying, a tank sweep (~$200–$500) finds buried tanks before closing.

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