How long a full 275-gallon oil tank lasts
Approximate days from a typical full delivery of 248 gallons, if heating oil heats the home and its hot water.
| Weather | Small home | Average home | Large home | Very large home |
|---|---|---|---|---|
| Mild — around 50°F | 225 days | 158 days | 115 days | 90 days |
| Cool — around 40°F | 158 days | 105 days | 74 days | 58 days |
| Cold — around 30°F | 121 days | 79 days | 55 days | 42 days |
| Very cold — around 20°F | 99 days | 63 days | 44 days | 33 days |
| Bitter — around 10°F | 83 days | 53 days | 36 days | 28 days |
Home sizes: small about 1,200 sq ft, average 2,000, large 3,000, very large 4,000. Older, draughty homes use more; well-insulated homes with efficient equipment use less.
How we work it out
Heating use rises as it gets colder outside. We estimate daily use from the gap between 65°F and the average outdoor temperature, scaled to your home's size, plus a small amount for hot water. The rates come from the U.S. Energy Information Administration's figures for how much heating oil the average heated home uses in a winter. If you know your own use from past delivery tickets (gallons delivered ÷ days since the last delivery), type it in for a more accurate answer.
Oil gauges show how high the oil is, not the gallons — so we convert your reading with the same tank geometry as our oil tank chart. We count the time until your gauge reaches 1/4, when most dealers suggest ordering.
Common questions
How long will 100 gallons of heating oil last?
For an average-size home (about 2,000 sq ft) that also uses heating oil for hot water, about 43 days at 40°F, 32 days at 30°F and 26 days at 20°F.
How long does a 275-gallon oil tank last?
A typical delivery fills it with about 248 gallons. In an average home that lasts roughly 79 days in cold (30°F) weather and 158 days in mild weather.
How long will a quarter tank of oil last?
A quarter on the gauge of an upright 275-gallon tank is about 58 gallons — roughly 19 days for an average home at 30°F. Order before it gets that low in cold weather.
What will my next delivery cost?
This week's U.S. average is $6.23 a gallon before tax. Pick your state in the calculator above, or see heating oil prices by state.
Heat with propane? See how long a propane tank lasts.