Power from Electricity Meter Pulses Calculator (LED Blinks or Disc Turns)
The power in watts that an appliance or a whole home is drawing, from the blinks of the meter's LED or the turns of its disc, with the yearly energy and cost that implies.
Results
What this tool does
Every meter states its own pace: 1000 imp/kWh means one blink per watt-hour, so a blink every 3.6 seconds is exactly 1000 W. Switch everything else off, count the blinks over a minute or so, then switch the appliance on and count again — the difference is its real draw, which a plug-in watt meter cannot show for a hard-wired oven, heat pump or water heater. An old electromechanical meter works the same way with disc turns per kWh, printed on its face. Loads that cycle, like a fridge compressor or a heating element, need a longer count to average out.
Formula
P = 3 600 000 × n ÷ (t × k) W · energy per pulse = 1000 ÷ k Wh
Variables
| Symbol | Meaning | Unit |
|---|---|---|
n | Pulses counted (LED blinks or disc turns) | — |
t | Time the count took | s |
k | Meter constant (pulses or disc turns per kWh) | /kWh |
h | Hours a day it runs | h |
pr | Price of a kWh | — |
P | Power being drawn | W |
EP | Energy in one pulse | Wh |
SP | Time between pulses | s |
KY | Energy over a year at that use | kWh |
CY | Cost over a year at that use | — |
Worked example
- Pulses counted (LED blinks or disc turns)10
- Time the count took36 s
- Meter constant (pulses or disc turns per kWh)1000 /kWh
- Hours a day it runs4 h
- Price of a kWh0.2
- Power being drawn1000 W
- Energy in one pulse1.000 Wh
- Time between pulses3.60 s
- Energy over a year at that use1460 kWh
- Cost over a year at that use292.00
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- Prices and emission factors are yours to enter. The tool ships with no tariff table and assumes nothing about your country or supplier, so change the defaults to match your own bill.