WATER HEATING CALCULATOR
Electric Water Heater Cost Calculator
Use heating-element wattage, active runtime, and your rate to calculate water-heating cost.
✓ Free✓ Instant results✓ No sign-up
ADVERTISEMENT
LIVE CALCULATOR
Updates instantlyEstimate hot-water electricity use
watts
hours
days
$/kWh
Formula: Monthly cost = (watts ÷ 1,000) × active hours per day × days × electricity rate
ADVERTISEMENT
How this estimate works
Tank heaters cycle to replace used hot water and standby losses. Active runtime differs from hours switched on.
- Use your equipment data. Check a label, specification sheet, controller, or energy meter.
- Enter your utility rate. A recent bill is more useful than a national average.
- Test different schedules. Change one input at a time to compare scenarios.
Ways to reduce or refine the cost
1
Use a safe temperature setting.
2
Fix hot-water leaks promptly.
3
Use low-flow fixtures and cold laundry cycles when appropriate.
Transparent methodology
Results use the values you enter and standard energy formulas. They are planning estimates, not bills or guarantees.
Frequently asked questions
Do both elements run at once?+
Many standard tanks operate one element at a time, but designs differ.
Is a heat-pump water heater calculated the same way?+
No. Its labeled annual kWh is usually a better input.
Why is my bill different?+
Demand, inlet temperature, tank size, settings, and standby loss affect consumption.