Example 1
P = 2000 W, t = 150 s -> W = 300000 J.
Engine work calculator
Type power P [W] and time t [s]. The calculator computes work W = P·t: 2000 W and 150 s is 300,000 J, and 500 W and 7200 s is 3,600,000 J, or 1 kWh. Zero seconds gives zero joules.
Power from work: P = W/t. Time from this pair: t = W/P.
Result
Power P (W) and Time t (s). The result shows up here.
How it works
Work from steady power is W = P t. At 2000 W and 150 s you get 300000 J. At 100 W and 3600 s you get 360000 J. At 500 W and 7200 s you get 3600000 J, or 1 kWh. 1 kWh = 3.6·10^6 J. 40 W for 86400 s is 3456000 J, a little under 1 kWh.
The form has two fields: P in watts and t in seconds. Type 1.5 kW as 1500, not as 1.5. One hour is 3600 s, not 1 in the t field. The result is in joules. A comma and a period are the same P: 1500,5 and 1500.5.
P and t must be positive. Zero power or zero time says nothing about work. Both fields need a number before 300000 J can appear. The formula takes steady P. If power jumps, that is an integral, not this product.
P = W/t and t = W/P live next door: the same trio, a different unknown. W = F s is force along a path, not power times time. Same unit: joule.
1 kWh at 500 W is exactly 7200 s. This calculator does not price a tariff. It stays with joules from P and t.
Type 2000 and 150, click Calculate, and match 300000 J. The header symbol does not turn a shaft. Treat the result as energy at steady power, not as an instant of torque.
How to use
- In the first field enter P in watts, for example 2000. 1.5 kW is 1500, not 1.5.
- In the second field enter t in seconds, for example 150. One hour is 3600, not 1.
- Click Calculate. The calculator multiplies P by t. 2000 W and 150 s give 300000 J.
- P and t must be positive. Both fields need a number. The formula assumes steady P.
- For P = W/t, open power from work. Time from this pair is on t = W/P. Here it stays W.
Formula
W = P·t
P > 0, t > 0. Unit of W: joule. 1 kWh = 3.6·106 J.
Engine W from P and t
The pair of t = W/P: here W = P·t. 2000 W and 150 s is 300000 J. 500 W and 7200 s is 3600000 J, or 1 kWh.
- W
- Engine work [J]. 2000 × 150 = 300000 J. 1 kWh = 3.6e6 J.
- P
- Engine power [W]. 2000 W or 500 W. P must be positive.
- t
- Run time [s]. 150 s or 7200 s (two hours). t must be positive.
Real-life examples
Example 2
P = 100 W, t = 3600 s -> W = 360000 J.
Example 3
P = 1500 W, t = 60 s -> W = 90000 J.
Example 4
P = 75000 W, t = 10 s -> W = 750000 J.
Example 5
P = 1 W, t = 1 s -> W = 1 J.
Example 6
P = 500 W, t = 7200 s -> W = 3600000 J = 1 kWh.
Example 7
P = 3000 W, t = 30 s -> W = 90000 J.
Example 8
P = 40 W, t = 86400 s -> W = 3456000 J.
Ways to use this calculator
- You compute 300000 J from 2000 W for 150 s.
- You check 1 kWh: 500 W and 7200 s.
Frequently asked questions
How much W at 2000 W and 150 s?
Work is 300,000 J. That is the product 2000 × 150. Same pair as P = W/t on the power card, only the unknown is W.
Which units do I type?
Power P [W], time t [s]. Result W [J]. Type an hour as 3600, and 1 kWh as 3,600,000 J, not as 1.
What if t = 0?
Work is 0 J. No time means no work done. Both fields still need a number.
How is this different from P = W/t?
The calculator multiplies power by time and get work. There you divide work by time and get power. Same triple, different unknown.
How is this different from W = F·s?
Here work comes from power and time, joules from watts. There work is force along a path. Different fields, same unit W [J].
Where does 1 kWh at 500 W and 7200 s come from?
500 × 7200 = 3,600,000 J. That is one kilowatt-hour. Two hours at 500 W is exactly 1 kWh.
Does a comma in 1500.5 W work?
Yes. 1500.5 and 1500,5 are the same P [W]. A comma and a period mean the same value.
How much at 40 W and 86400 s?
Work is 3,456,000 J. Forty watts for a day, a little under 1 kWh.
Can power jump over time?
The calculator uses a steady P. If power jumps you need the integral of P dt, which is not here. Type the average P on interval t.
Where is t = W/P?
On the time-from-work-and-power page. There you solve for t. Here the unknown is W.
Knowledge sources
The formula is the school one. Units follow SI; NIST SP 330 and BIPM define the measures, not your result.
Page updated in 2026.