A blanket averaging 100 watts for four hours uses 0.4 kWh and costs 8 cents at $0.20 per kWh. Use your own blanket’s wattage, operating time and electricity rate to estimate its cost. A heated throw warms a person rather than a whole room, so a lower energy bill is possible only when it replaces some other heating.
The numbers below are transparent U.S.-dollar examples, not a measured test of every blanket or a national price average. Controls cycle, products differ, and the setting marked low is not a universal wattage.
The Electric Blanket Electricity Cost Formula
Cost = average watts ÷ 1,000 × operating hours × electricity rate. For a 100-watt average over four hours: 100 ÷ 1,000 × 4 = 0.4 kWh. Multiply by $0.20/kWh to get $0.08. Repeated daily for 30 days, that becomes 12 kWh and $2.40 per month.
Start with the rating printed on the product or its official specifications. A currently listed 100-watt heated throw provides a real example of nameplate power, but that does not mean every blanket draws 100 watts continuously. The rating and your actual average use answer different questions.
| Assumed average power | 4 hours daily, 30 days | At $0.20/kWh | At $0.35/kWh |
|---|---|---|---|
| 50W | 6 kWh | $1.20 | $2.10 |
| 100W | 12 kWh | $2.40 | $4.20 |
| 150W | 18 kWh | $3.60 | $6.30 |
These are alternative assumptions, not measured low, medium and high settings of one product. Where your rate changes by time of day, price the energy in the periods when you actually use the blanket. Our electricity cost calculator can help with wattage-and-hours estimates.
Related reading: monthly electric heating costs.
Why the Nameplate Can Overstate Everyday Consumption
A controller can switch heat on and off after warming up. If a hypothetical 100-watt product draws full power for half of a four-hour session, its heating energy would be 0.2 kWh before any controller consumption. That is an illustration of duty cycle, not a promise of 50% operation.
Preheating, room temperature, chosen setting and the manufacturer’s permitted arrangement can change consumption. Do not fold or cover a blanket contrary to its instructions to force a lower reading. A safe operating setup takes priority over shaving a few cents from an estimate.
If measurement is needed, use only equipment and connections permitted by the blanket manufacturer. A rating-based upper estimate is often sufficient for a budget. There is little value in buying an extra monitoring device just to measure a very small load unless you have other uses for it.
Compare the Blanket With a Space Heater Fairly
Assume a blanket averages 100 watts while a heater continuously draws 1,500 watts, each for four hours. The blanket uses 0.4 kWh; the heater uses 6 kWh. At $0.20/kWh, their energy costs are $0.08 and $1.20. The difference is $1.12 per session, or $33.60 over 30 identical sessions.
That comparison describes unequal heating services. The heater warms room air and surfaces; the blanket provides local warmth. It does not prove a blanket can replace room heating in every household. If the heater cycles for only half the session, its example cost falls to $0.60 and the difference falls to $0.52.
For a fuller heater calculation, see how much a 1,500-watt space heater costs to run. Avoid comparing a blanket’s cycling average against a heater’s maximum rating while presenting both as measured real-world use.
Will It Actually Lower the Whole-House Bill?
If the main heating system runs exactly as before, the blanket adds electricity. Savings require a real change, such as replacing a period of portable-heater use or reducing room-heating demand where safe and suitable. The avoided heating cost must exceed the blanket’s added cost.
Keep occupied rooms at a suitable temperature and protect the building from cold-related damage. A blanket does not heat plumbing, manage dampness or provide comfortable conditions for everyone else in the home. It is especially inappropriate to calculate whole-house savings as though all space heating can be eliminated.
If the bill rises even though your recorded consumption does not, inspect the tariff and billing period separately. Our guide to higher bills with the same kWh usage explains why appliance savings and final bill changes can diverge.
A Simple Purchase Payback Check
Suppose a blanket costs an assumed $60 and genuinely avoids $0.80 of other heating each day while adding $0.08. The net daily reduction is $0.72, giving a simple energy-only payback of 60 ÷ 0.72 = about 84 days of that use. If no heating is displaced, there is no energy-savings payback.
Purchase for the actual person and use case, not the largest advertised savings percentage. Follow the exact product’s safety, washing, controller and user-eligibility instructions. Stop using damaged bedding or cords. Automatic shutoff is a feature to understand, not permission to ignore the manual.
About the Author
JHOTAS-LAB is written by an electrical-construction and project-coordination practitioner in South Korea. This U.S.-focused guide combines official documentation with clearly stated calculation assumptions; it does not describe personal U.S. installation experience.
Sources & Official References
Sunbeam Home — 100W Heated Throw Specifications
Sunbeam — Product Instruction Manuals
Hawaiian Electric — Calculate Appliance Operating Costs
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