1. How long will my heating oil last?
Enter how much oil is in your tank today and how much you burn in a year; the calculator returns the date the tank would run dry, the day you reach your reserve and the last day to order given your delivery time. Your yearly use is on past delivery notes or your supplier account; read today's level from the gauge or dip the tank.
UK and Ireland, in litres
US Northeast, in gallons
Leave the hot-water box ticked if your oil boiler also heats your water, because it then burns oil in summer too. The UK version starts with a 200-litre reserve and 14 days' delivery, the US version with 50 gallons and 7 days. Those are our defaults, not published averages: we found no current delivery-time figures for either country, so ask your supplier and change them. The quantities you type are neither stored nor sent anywhere.
2. When will my oil tank run out? Two worked examples
A UK home starting with 1,000 litres and burning 2,000 litres a year runs dry around 14 February 2027; a Northeast home with 150 gallons and 500 gallons a year around 27 December 2026 (our calculation, start date 23 September 2026). Both sets of inputs illustrate the method; they are not typical households.
| Input and result | UK | US Northeast |
|---|---|---|
| In the tank on 23 Sep 2026 / use per year | 1,000 L / 2,000 L | 150 gal / 500 gal |
| Hot water from the oil boiler | yes | yes |
| Reserve / delivery time | 200 L / 14 days | 50 gal / 7 days |
| Use on 23 Sep 2026 | 3.39 L a day | 0.54 gal a day |
| 23 to 30 September | 27 L | 4 gal |
| October | 158 L | 34 gal |
| November | 211 L | 52 gal |
| December | 244 L | 60 gal* |
| January | 263 L | – |
| Reserve reached around | 20 Jan 2027 | 6 Dec 2026 |
| Order by | 6 Jan 2027 | 29 Nov 2026 |
| Tank empty around | 14 Feb 2027 (144 days) | 27 Dec 2026 (95 days) |
* The tank runs dry during this month.
The UK home already burns 3.39 litres a day in late September because British heating need is spread over more months: October to April holds 820 per mille of the UK year, against 924 per mille in the US Northeast profile (our sums from the table below). The US example assumes 500 gallons a year, which is less than the EIA average points to (see below); if you burn more, enter your own figure.
3. How does the calculator work out heating oil usage per day?
Instead of dividing your yearly use by 365, the calculator weights each month by its share of long-term heating degree days: January carries 146 per mille of the UK year and 191 per mille of the US Northeast year, July 19 and 1. Heating degree days measure how cold it was. For the UK and Ireland we use Eurostat's series nrg_chdd_m, which adds up 18 °C minus the daily mean on every day with a mean of 15 °C or less; we averaged ten full years, 2016 to 2025 (dataset updated 8 May 2026). For the Northeast we use NOAA's 1991–2020 monthly normals on a 65 °F base for Boston Logan and Portland, Maine, and average the two profiles.
Hot water is a flat base load. The German non-profit co2online puts average oil use at 17 litres per square metre a year with hot water and 13 without; from that we derive that about 24% of annual use does not depend on the weather. The formula: use per day = annual use × (0.24 ÷ 365 + 0.76 × monthly share ÷ days in month). Untick hot water and the first term drops out.
| Month | United Kingdom | Ireland | US Northeast |
|---|---|---|---|
| January | 146 | 141 | 191 |
| February | 124 | 121 | 164 |
| March | 124 | 125 | 145 |
| April | 102 | 101 | 90 |
| May | 66 | 69 | 45 |
| June | 34 | 38 | 11 |
| July | 19 | 20 | 1 |
| August | 20 | 19 | 2 |
| September | 41 | 44 | 17 |
| October | 77 | 79 | 63 |
| November | 113 | 112 | 110 |
| December | 134 | 131 | 161 |
| October to April | 820 | 810 | 924 |
| May to September | 180 | 190 | 76 |
Per mille of annual heating need; each column sums to 1,000 (largest-remainder rounding). UK and Ireland: Eurostat, our calculation. US Northeast: NOAA NCEI normals, mean of Boston and Portland, Maine. Season totals are our sums.
4. How much heating oil does a home use, and how big is a typical tank?
A UK home typically burns 1,500 to 2,500 litres of heating oil a year, about 2,000 litres for a three-bedroom semi-detached house, according to the comparison site OilCompare; we found no official average from OFTEC, the Energy Saving Trust or the government. According to the supplier Certas Energy, tanks hold between 1,000 and 2,500 litres of kerosene and the minimum order is 500 litres. Aberdeenshire Council advises ordering before the tank drops below a quarter full, which is 250 litres on a 1,000-litre tank and 625 on a 2,500-litre one (our arithmetic).
In the US, the EIA's winter fuels table puts use at 442 gallons per household heating mainly with oil from November 2025 to March 2026, a national average; about 3.564 million Northeast households heated with oil in 2025/26, down from 4.449 million in the winter of 2020/21. Over those 151 days that is about 2.9 gallons a day, so 100 gallons lasts roughly 34 days at the winter average (our calculation). November to March holds 78.6 per cent of normal heating degree days in Boston and 75.6 per cent in Portland (our calculation from NOAA normals), so 442 gallons would point to roughly 560 to 585 gallons a year; that is our rough, unverified estimate, with hot water not split out. A 275-gallon tank, the most common size, holds only about 225 usable gallons (Burt's Reliable). One US gallon is exactly 3.785411784 litres (derived from NIST definitions).
5. How accurate is the result, and when should you order?
The result describes an average year, not a promise: between 2016 and 2025 the UK's annual heating degree days ranged from 2,710 to 3,004 and Ireland's from 2,418 to 2,772 (Eurostat). The coldest year was about 5 per cent above the average in both (our calculation), and a winter like that empties the tank sooner. The 24% hot-water share is an average; yours may be higher or lower. Gauges are rough: on a 275-gallon tank a reading of one half means about 110 gallons (Burt's Reliable). Running dry costs more than the oil, because the boiler then has to be re-primed, which is an extra charge (Aberdeenshire Council). The Northeast profile comes from two New England stations, so elsewhere treat it as an approximation.
When to order is also a price question; Heating oil: buy now or wait? sets out the trade-offs, and if you fill up early it helps to know how long heating oil keeps. Countries do a similar sum, stock divided by daily net imports or daily use, and call the result days of supply. How many days national emergency stocks cover is tracked in the Oil Reserves Monitor, with product-level figures on diesel, heating oil and jet fuel stocks.
How to cite: Global Oil Shock (Jörg Dässler), “How Long Will My Heating Oil Last? Tank Calculator”, as of 23 Sep 2026, https://globaloilshock.com/en/strategic-oil-reserves/heating-oil-tank-calculator/