kWh to kW Calculator
Convert kilowatt-hours and duration into average kilowatts. Clarifies energy vs power for metering and solar sizing. Runs locally in your browser.
Trust summary Engine tested · Source checked · v1.2.1
- Input interpretation
- Enter values to calculate.
- Result
- —
- Model
- Average power in kW from energy (kWh) and time (h), or energy from power and time.
- Scope
- Power is the average over the stated period
- Verification
- Engine tested · Source checked · v1.2.1
- Named expert review
- Optional · Not performed
Formulas
Core equations used by this calculator.
How to use
Choose kWh → kW or kW → kWh
Forward needs energy and time; reverse needs power and time.
Enter energy (or power) and hours
Convert minutes to hours (minutes ÷ 60). Use 24 for a full day.
Read average kW or total kWh
kWh → kW gives average power over that period — useful for solar and load sizing.
Example calculations
Common configurations with formula and result.
Daily average from bill energy
48 kWh over 24 hours
Air conditioner energy
1.5 kW × 5 h
100 kWh in 10 hours
Sustained load check
Battery pack average draw
1 kWh over 5 hours
100 kWh in 1 hour
Peak-style average
100 kWh → average kW by duration
Common values at a glance.
| Energy | Time | Average power |
|---|---|---|
| 100 kWh | 1 h | 100 kW |
| 100 kWh | 2 h | 50 kW |
| 100 kWh | 4 h | 25 kW |
| 100 kWh | 5 h | 20 kW |
| 100 kWh | 8 h | 12.5 kW |
| 100 kWh | 10 h | 10 kW |
| 100 kWh | 24 h | 4.17 kW |
| 100 kWh | 50 h | 2 kW |
| 100 kWh | 100 h | 1 kW |
| 48 kWh | 24 h | 2 kW |
kWh to kW calculator specification
Version 1.2.1 · Engine tested
- Engine tested 13 published cases
- Named expert review Not performed
- Calculation version 1.2.1
- Definition
- Kilowatt-hours (kWh) measure energy — power used over time. Kilowatts (kW) measure power — the rate of energy use. You cannot convert kWh to kW without a time period: average power kW = kWh ÷ hours. This calculator also reverses the relation: energy kWh = kW × hours.
- What it calculates
- Average power in kW from energy (kWh) and time (h), or energy from power and time.
- Inputs
- Energy E (kWh) or power P (kW)
- Time t (hours)
- Outputs
- Average power in kW
- Energy in kWh
- Formula
P = E / t; E = P × t- Assumptions
- Power is the average over the stated period
- Time is expressed in hours
- Units
- kWh, h → kW
- Boundary conditions
- kWh→kW (quotient): time t = 0 → 0 kW — soft
- Zero energy → 0 kW
- kW→kWh (product): zero power or time → 0 kWh
- Result is average power over the interval, not instantaneous peak
- Example
- 48 kWh ÷ 24 h = 2 kW
- Validation cases
13 published on this page
- 48 kWh, 24 h → 2 kW
- 100 kWh, 10 h → 10 kW
- 100 kWh, 1 h → 100 kW
- 1.5 kW, 5 h → kWh → 7.5 kWh
- 1 kWh, 5 h → 0.2 kW
- 96 kWh, 24 h (2× energy) → 4 kW (linear in E)
- 48 kWh, 12 h (half time) → 4 kW (inverse in t)
- 48 kWh, 0 h → 0 kW (soft: zero time → 0)
- 0 kWh, 24 h → 0 kW
- 0 kW, 24 h → kWh → 0 kWh
- 2 kW, 0 h → kWh → 0 kWh
- 48 kWh → 2 kW → kWh round-trip at 24 h → 48 kWh
- 2 kW, 24 h → kWh → 48 kWh
- Sources
- Energy–power identity — E = P × t with coherent units (kWh, kW, h)Supports: kW = kWh / h; kWh = kW × h
- NIST Guide to the SI (SP 811) — Watt, joule, and watt-hour relationshipsSupports: 1 kWh = 3.6 MJ; power as energy per time
- IEC 60050 — International Electrotechnical Vocabulary — Active power (IEV 131-11-42) · accessed 2026-09-05Supports: P is active power; unit watt (W); kW is 10³ scale
- IEC 60050 — International Electrotechnical Vocabulary — Watt hour (IEV 131-11-58) · accessed 2026-09-05Supports: 1 Wh ≔ 3600 J; kWh is the common multiple. P(kW) = E(kWh)/t(h) at constant power
- BIPM SI Brochure (9th edition, version 4.01) — Watt, joule, and hour · 2026-06
·
DOI
· accessed 2026-09-05Supports: P = E/t; 1 kWh = 3.6 MJ
- Energy–power identity — E = P × t with coherent units (kWh, kW, h)
- Calculation version
- 1.2.1
Background
Interpretation and common distinctions.
Convert kilowatt-hours (kWh) to kilowatts (kW) — or reverse — using time:
P((kW)) = (E((kWh)))/(t((h))) E((kWh)) = P((kW)) × t((h))
Default example: 48 kWh over 24 hours → 2 kW average.
kWh vs kW
| Unit | Quantity | Meaning |
|---|---|---|
| kW | Power | Rate of energy use or generation |
| kWh | Energy | Power × time (what utilities usually bill) |
One kilowatt-hour is the energy of 1 kW running for 1 hour. They are not interchangeable without a duration.
Why this matters for solar and bills
- Utility bills report kWh; dividing by hours (or days × 24) estimates average demand in kW.
- Solar / battery sizing often starts from daily kWh, then relates array or inverter power (kW) and storage (kWh).
- For cost, multiply kWh by your rate in the energy cost or electricity calculators.
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Frequently asked questions
Key distinctions behind the calculation.
How do I convert kWh to kW?
Divide energy by time in hours: kW = kWh ÷ h. Example: 48 kWh over 24 h → 2 kW average.
Can I convert kWh to kW without time?
No. kWh is energy and kW is power — different quantities. You always need a time period (or an assumed duration).
What is the difference between kWh and kW?
kW is how fast energy is used (power). kWh is how much energy is used over time. A 2 kW heater running 3 hours uses 6 kWh.
Is the result average or peak power?
Average power over the interval you entered. Peaks can be higher if the load cycles or surges.
How do I convert kW back to kWh?
Multiply: kWh = kW × hours. Example: 1.5 kW for 5 h → 7.5 kWh.
How does this help with solar sizing?
Daily kWh from a bill ÷ sunlight or usage hours estimates average demand. Pair with panel watts and battery kWh for system sizing — this tool only does the energy ↔ power step.
What if my time is in minutes?
Convert to hours first: hours = minutes ÷ 60. Example: 30 minutes = 0.5 h.
How do I get watts instead of kW?
Average watts = (kWh × 1000) ÷ h, or multiply this calculator’s kW result by 1000. See kWh to watts.