TOOLS
Kalkulačka nákladů na elektřinu na osvětlení
Estimate running costs. Compare setups. See what a change could save.
Your setup
How do you know the power?
LED strip length (m)
5 m
5 m
Total lit length.
LED strip power (W/m)
From the strip specification. Not the PSU rating.
Input power per fixture (W)
Number of fixtures
Measured total input power (W)
Hours per day (h)
Days per year (days)
Electricity price (applies to all groups and both setups)
Price per kWh
Currency
Use your bill’s energy unit rate. Example: 20 cents/kWh = 0.20 USD/kWh. Changing currency changes the label only.
Power settings
Driver efficiency (%)
Whole-group standby power (W)
Your running cost · Updates as you type
ESTIMATED ANNUAL ELECTRICITY COST
$46.72 USD / year
233.6 kWh / year
Total input while on
80 W
Hours per year
2,920 h
Electricity use and cost by period
| Period | Energy | Náklady |
|---|---|---|
| Daily average | 0.64 kWh | $0.13 |
| Monthly average | 19.47 kWh | $3.89 |
90% driver efficiency assumed · No standby power entered
Compare a setup
Calculation details
How it is worked out
Total input power
Wall input
Energy
Náklady
Daily = one day of use; Monthly = daily × 365/12. Flat-rate estimate; no tariff lookup.
Total input power
P = strip length × W/m (or fixtures × their wattage, or your measured figure).Wall input
P_in = P ÷ driver efficiency + standby power.Energy
E = P_in (W) × hours/day × days/year ÷ 1000 (kWh).Náklady
= E × price per kWh.Daily = one day of use; Monthly = daily × 365/12. Flat-rate estimate; no tariff lookup.
Good to know
Which power figure should I enter?
Enter the power the lighting actually draws, not the power supply rating. For a strip use length × W/m from the specification; for individual fittings use input power per fixture × count; or use a measured total. Entering the PSU rating instead of the real draw overestimates the running cost.
Does 50% brightness mean half the cost?
Not usually. Most constant-current drivers do not halve the input power at 50% brightness – the driver and control gear still draw a baseline. Use the measured input power at the brightness you actually run for the most accurate estimate.
What does driver efficiency change?
A 90% efficient driver needs roughly 11% more wall power than the LEDs alone. If you enter 80 W of LED load and 90% efficiency, the wall draw is about 89 W before standby. Include driver losses for a realistic bill estimate.
Which electricity price should I use?
Use the energy unit rate from your electricity bill (the “kWh” line), not the standing charge. Prices vary by country, tariff and time of day – a flat-rate average is fine for planning. Changing the currency only changes the label, not the math.
How are monthly costs and standby calculated?
Daily energy is one day of use; monthly energy is the daily figure × 365/12. Standby power is added to the wall draw whenever the group is “on”. The estimate excludes fixed charges, demand charges and maintenance.
What does the payback figure include?
Payback divides the extra upfront cost of the alternative by the annual saving in running cost, giving the years to recover the extra spend. It only counts electricity – maintenance, lifespan and labour differences are not included.
Planning the wiring? Use the LED voltage drop calculator.
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