Deep freezer
How much electricity does a deep freezer use?
100–300 W running · 0.4–1.5 kWh/day · $2–$7 per month
Deep freezers are efficient by design: a top-opening chest holds cold air in place, a full freezer has real thermal inertia, and the compressor only cycles a few times an hour.
Energy by size
- 3–5 cu ft: 0.3–0.6 kWh/day
- 7 cu ft: 0.5–0.9 kWh/day
- 10–15 cu ft: 0.8–1.5 kWh/day
New vs old is the whole story
A freezer built before 2000 can use three times the energy of a current model of the same size. If you are running an inherited freezer, comparing its label consumption with a modern unit's annual kWh figure is the fastest way to decide whether to replace it — the difference is often $60–120 a year.
Keeping it cheap to run
- Keep it full — frozen mass stabilises temperature, so the compressor runs less
- Defrost regularly — more than 1 cm of ice noticeably reduces efficiency
- Check the seal — a sheet of paper should resist being pulled out when the door is closed
- Keep it out of hot spaces — a garage in summer is the worst location
Frequently asked questions
How many watts does a deep freezer use?
100–300 W running. The figure on the rating label is the maximum draw; actual use varies with settings, age and usage pattern.
How much does it cost to run a deep freezer per month?
With the defaults above it comes to the monthly figure shown in the calculator. At 16.5¢/kWh — the US residential average — that is a realistic middle estimate. Your own bill may be 30% lower or higher depending on state.
Is it cheaper to run a deep freezer at night?
Only if your utility offers a time-of-use plan and you avoid the 4pm–9pm peak window. On a flat-rate plan, the time of day makes no difference to the total.
Does the calculator account for real-world duty cycles?
Not automatically — you enter the effective hours yourself. For compressing appliances like refrigerators and AC units, enter the running watts and roughly the proportion of time the compressor is on, which is usually 30–50%.
Will a newer deep freezer actually save money?
Compare the kWh figure in the calculator against an Energy Star model's stated annual use. If the difference is a few hundred kWh a year, the payback on a replacement is usually long; if it is over 500 kWh, it is worth pricing out.