How Long Does a Tank of Heating Oil Last on Long Island?
From the Alcus family · Alcus Fuel Oil & Sons, Amityville · Updated October 30, 2026
The short answer: a full 275-gallon tank lasts most Long Island homes somewhere between 4 and 8 weeks in the middle of winter, and a lot longer in fall and spring. The real number depends on your house and the weather.
What changes how fast you burn oil
- The weather. Oil use rises fast as temperatures drop. A week in the 20s can burn two or three times what a week in the 40s does.
- House size and insulation. Older capes and colonials near the water usually burn more than newer, tighter homes.
- Hot water. If your boiler also heats your water (a tankless coil or indirect tank), you burn oil all year, even in summer.
- Thermostat setting. Each degree you turn down for long stretches saves a little oil.
- The boiler or furnace itself. A dirty burner or an old, oversized boiler wastes oil. A yearly tune-up keeps it efficient.
Rough numbers for a Long Island home
| Weather | Typical gallons per day | 100 gallons lasts about |
|---|---|---|
| Mild fall or spring day (50s) | 1–3 | 5–10 weeks |
| Normal winter day (30s) | 3–5 | 3–5 weeks |
| Cold snap (teens–20s) | 6–8+ | about 2 weeks |
Estimates for an average-size South Shore home. Your home may be higher or lower. Try our heating oil calculator for your own numbers.
How much oil is actually in a "full" tank?
A standard basement tank is 275 gallons, but it's never filled to the brim — there has to be room for expansion. A full 275 usually holds around 225–250 gallons. Some homes have a 330-gallon tank, two tanks, or a larger outdoor tank. Not sure? Our driver can tell you, or see how to read your oil tank gauge.
Don't wait for empty
Running out of oil means no heat, a possible service call to restart the burner, and the risk of pulling sludge from the bottom of the tank into the oil line. Order at 1/4 tank, or let us do the watching with automatic delivery. Already out? Read what to do if you run out of oil.
Need oil or service on the South Shore?
Questions
How long do 100 gallons of heating oil last?
In a typical Long Island home, 100 gallons lasts roughly 2–4 weeks in mid-winter and much longer in fall or spring. A small, tight house lasts longer; a large or drafty one, or one that also heats water with oil, goes faster.
How many gallons of oil does a house use per day in winter?
A typical South Shore home might burn 2–3 gallons on a mild day and 6–8 or more on a very cold one. Your own number depends on size, insulation, thermostat setting and whether the boiler also makes your hot water.
When should I order heating oil?
Order when your gauge reads about 1/4. That leaves a cushion for a cold snap or a busy delivery week. Automatic delivery customers don't have to watch the gauge at all.