Conversion chartLow code sensitivityLast reviewed June 1, 2026
Electrical reference chart
Energy and kWh Conversion Chart
Use this energy and kWh conversion chart after the calculator result to document load watts, runtime, kWh, rate basis, and whether the value is energy only or cost-ready.
Quick reference table
Energy is power over time. Convert watts to kilowatts by dividing by 1,000, then multiply by hours to get kWh. Use this chart as the unit worksheet, and use the calculator result when runtime, duty cycle, appliance assumptions, and utility rate need to be recorded together.
Power, runtime, and kWh conversions
| Load | Runtime | Energy | Cost calculator input |
|---|---|---|---|
| 100 W | 10 hours | 1.0 kWh | Use 1.0 kWh before rate is applied |
| 500 W | 4 hours | 2.0 kWh | Use 2.0 kWh before rate is applied |
| 1,000 W | 1 hour | 1.0 kWh | Use 1.0 kWh before rate is applied |
| 1,500 W | 2 hours | 3.0 kWh | Use 3.0 kWh before rate is applied |
| 5,000 W | 0.5 hour | 2.5 kWh | Use 2.5 kWh before rate is applied |
Energy result context checks
| Calculator result shows | Record next | Why it matters |
|---|---|---|
| kWh for one cycle | Cycles per day or billing period | A single cycle is not the same as monthly energy use |
| kWh from nameplate watts | Whether the load runs steadily or cycles | Nameplate watts can overstate real energy for cycling appliances |
| Cost estimate | Utility rate, period, and any excluded charges | kWh cost is not the full bill when demand or fixed fees apply |
| Comparison between loads | Same runtime and rate assumptions for each option | Different assumptions can make comparisons misleading |
Energy kWh chart to calculator handoff
| Search intent | Open the calculator when | Keep on this chart |
|---|---|---|
| Watts to kWh conversion | Runtime, duty cycle, or billing period needs to be entered with the load | W, hours, and unit conversion math |
| Appliance energy estimate | Nameplate watts need cycles per day or measured runtime assumptions | Load source and operating mode |
| Electricity cost screen | kWh must be multiplied by a utility rate or compared across scenarios | Energy-only value and excluded bill charges |
| Monthly usage comparison | Daily or cycle kWh must roll up to a week, month, or billing period | Same runtime basis for every comparison |
Formula basis
kWh = W x hours / 1000. Wh = W x hours. Cost = kWh x utility rate.
- W is load power in watts.
- hours is runtime for the period being estimated.
- kWh is kilowatt-hours used for most energy billing calculations.
- utility rate is the cost per kWh supplied by the user.
Worked examples
Assumptions. Balanced load and line-to-line voltage assumptions behind this chart.
- The chart assumes steady power draw during the runtime period unless the worksheet separately records cycling or variable operation.
- Real appliances may cycle, ramp, idle, or vary with controls and operating mode.
- Cost results do not include demand charges, taxes, minimum bills, fixed fees, or utility-specific tariff rules unless the related calculator records them.
Code and standard notes. Planning limits that should be checked before final equipment selection.
- This chart does not determine billing tariffs, demand charges, taxes, or utility-specific rate structures.
How to use this chart
Worksheet checklist. Record source basis, review gaps, and assumptions before using the chart result.
- Record load basisNote whether watts came from a nameplate, meter, estimate, appliance list, or calculated result.
- Record time periodWrite the runtime basis, such as hours per day, hours per cycle, shift hours, or hours per billing month.
- Apply rate separatelyCalculate kWh first, then apply rate and billing assumptions in the related cost calculator.
Common mistakes to avoid. Review these before turning chart current into an equipment decision.
- Multiplying watts directly by the utility rate without converting watt-hours to kilowatt-hours.
- Using nameplate watts as constant runtime power when the appliance cycles or changes operating mode.
- Comparing two cost results that use different runtime periods, utility rates, or duty-cycle assumptions.
Frequently asked questions
These answers explain how to use the chart without turning a quick reference into a final design decision.
Is kWh the same as kW?
No. kW is power at a moment in time. kWh is energy over time and is the value normally multiplied by an energy rate.
When should I use the cost calculator?
Use the cost calculator when the result needs a utility rate, billing period, appliance runtime, or comparison between load scenarios.
Why keep runtime separate from load watts?
The same wattage can produce very different kWh depending on hours of operation, duty cycle, and billing period.
When should I open the energy or cost calculator from this chart?
Open the calculator when the chart has watts, runtime, duty cycle, billing period, or utility rate assumptions that need to be stored with the kWh result.
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