Quick answer: Multiply the strip's watts per metre (W/m) by the length in metres to get the total wattage, then choose a driver rated higher than that total. For example, 4m of Polar X at 6 W/m is 24W, so it needs a 30W driver. If your total is close to a driver's limit, go up a size. The calculator below does the sum for any Sensio 24V strip.
Every LED strip has a power rating in watts per metre, shown in the specification on its product page. Once you know the length you are fitting, the wattage is a simple sum, and the wattage tells you which 24V LED driver to buy. Pick your strip, enter the length, and the calculator shows the total and the driver size.
LED strip calculator
metres
separate lengths of strip on this driver
The watts per metre in the calculator are taken from the specification on each strip's product page. The calculator covers our 24V strips only. 12V products are not included.
How the sum works
- Find the watts per metre. It is in the specification on every strip's product page, listed as wattage per metre.
- Multiply by the length. Watts per metre × metres = total watts. If you have several runs on one driver, add their lengths together first.
- Choose the next driver size above the total. A driver must be rated higher than the load on it. Sensio 24V drivers come in 6W, 15W, 30W, 60W and 150W. If you are close to the limit, or may add more strip later, go up a size.
Then check the pin type: 2-pin for single colour, 4-pin for CCT and 6-pin for RGBCCT. Our guide to what size LED driver you need covers mixing strip and lights on one driver, and lists the sizes each driver comes in.
Worked examples
Strip under a run of kitchen wall units
4m of Polar X at 6 W/m = 24W. Choose a 30W driver.
A longer run close to the limit
7.5m of Primo 2 at 3.6 W/m = 27W. A 30W driver is rated above that, but 27W is close to its limit, so a 60W driver is the safer choice.
Two shelves in an alcove
Two 2m runs of Radiant X at 4.8 W/m = 4m × 4.8 = 19.2W. Choose a 30W driver with at least two ports, or use a port expander.
LED strip wattage per metre
| Watts per metre | Sensio LED strip |
|---|---|
| 6 W/m | Polar X, Polar X Duo, Polar X IP65, Polar X Pro, Polar Pro, Razor, Razor X (2mm and 4mm), Razor X Duo (2mm and 4mm), Razor X Pro (2mm and 4mm), Delta, Ion 5, Ion 8, Flux |
| 5 W/m | Polar RGBCCT |
| 4.8 W/m | Radiant X, Radiant Pro, Sigma 2, Neutron |
| 4 W/m | Viva 3 |
| 3.6 W/m | Primo 2, Primo X, Dart |
See the full range of LED strip lights, or shop 24V LED drivers.
Frequently asked questions
How do I calculate the wattage of LED strip?
Multiply the watts per metre by the length in metres. For example, 5m of 4.8 W/m strip is 24W.
What size driver do I need for 5m of LED strip?
It depends on the strip. 5m of a 6 W/m strip is 30W, which is right at the limit of a 30W driver, so choose 60W. 5m of a 4.8 W/m strip is 24W, so a 30W driver is enough.
Can I run more than one length of strip from one driver?
Yes, as long as the total wattage stays below the driver's rating, the strips share the same pin type and there are enough ports. Port expanders add more connections.
Can I use a bigger driver than I need?
Yes. A driver only supplies the power the strip draws, so a larger driver is fine and leaves room to add more later.
Does the calculator work for 12V strip?
No. It covers our 24V strips only. A 12V strip needs a 12V driver. Read 12V or 24V LED strip lights for the difference.
Still not sure? Contact our technical team with your strip and lengths and they will size the driver for you.
