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Saving Energy & Utilities calculators
Estimate the cost of electricity, EV charging, lighting, and heating before you upgrade or cut back.
Reviewed by BoringToolsKit · August 24, 2026 · Planning information, not professional advice.
Saving Energy & Utilities: the big picture
Saving energy and cutting utility bills starts with understanding what each appliance actually costs to run. An appliance's wattage, your run time, and your electricity rate combine into a monthly cost you can usually reduce with small behavior changes. BoringToolsKit's energy calculators convert watts to cost, compare appliances, and project savings, so you can see which change pays off fastest.
- Cost = watts ÷ 1000 × hours × rate per kWh.
- BTU rating and efficiency (SEER/EER) drive cooling and heating cost.
- The fastest wins are often the highest-wattage, longest-running appliances.
- Find each appliance's wattage (on the label or nameplate).
- Convert watts and run time into a monthly cost at your rate.
- Compare changes — like a more efficient unit or shorter run time — to see the savings.
Worked example: the 1,500 W space heater
- Step 1: Electricity Cost Calculator — Enter 1,500 W, 6 hours a day, $0.16 per kWh See: About $1.44 a day — roughly $43 a month just for the heater
- Step 2: LED Savings Calculator — Swap a 60 W bulb for a 9 W LED, 5 hours a day at $0.16 See: About $15 a year saved per bulb
- Step 3: BTU Calculator — Size heating for a 200 sq ft room with average insulation See: The BTU target for comfortable, efficient heating
Numbers depend on the inputs you enter; the walkthrough shows one realistic scenario.