How Long Does a 275-Gallon Heating Oil Tank Last?
In cold weather a full 275-gallon heating oil tank usually lasts about 4–6 weeks, and one supplier puts a 2,000 sq ft home at 1–2 months across the winter. Mild weather stretches it to several months.
Burn rate by outdoor temperature
Commonly cited supplier charts give approximate daily use for an average home. Days below assume about 225 usable gallons, the figure some suppliers use for a 275-gallon tank (others say 250).
| Average outdoor temp | Gallons per day | Days |
|---|---|---|
| 15°F | 7.8 | 29 |
| 25°F | 6.2 | 36 |
| 35°F | 4.5 | 50 |
| 45°F | 2.8 | 80 |
| 50°F | 2.0 | 113 |
Reading your gauge
A quarter on the gauge is roughly 65–70 gallons, but less is usable. Suppliers treat a quarter tank as a warning level: in deep cold it may last only a few days to just over a week. Order at a quarter in winter, or sooner.
Whole-season use
One supplier estimates 800–1,000 gallons per season for a well-insulated 1,800 sq ft home and 1,200–1,500 gallons for a 2,500 sq ft home with average insulation. Use the tank duration calculator with your own burn rate.
FAQ
How many gallons is a quarter tank?
About 65–70 gallons on the gauge, with less usable at the bottom.
How long can heating oil sit in a tank?
One supplier says 18–24 months in a clean tank.
When should I order?
At a quarter tank in winter, or earlier if cold weather is forecast.