How to determine the voltage and wattage of a heater cartridge

I have a few loose heater cartridges without identification so I don't know their voltage or wattage rating. Can someone tell me how to test for these? I assume I will hook up a multimeter to the leads and look for some resistance value but I haven't been able to find the settings to use.

Thank you in advance or any help.

---

New browser from the creator of Opera: [vivaldi.com]

Measure Ohms on the lowest scale, it says 200 on my meter.
Then you can plug in the number to an online calculator like [rapid tables]. You can guess at voltage of 12 or 24 to get a reasonable wattage around 30-40 watts (which most rep rap heaters are).

Edit: You need two numbers entered to hit calculate and get a result, the others can remain blank.

Example: Say I measured 14.4 Ohms. If I plug in 12V to the calculator, that would be a 10 watt heater (likely not correct). But at 24V it's a 40 watt (correct).

Edited 2 time(s). Last edit at 06/01/2019 11:30PM by Diggrr.

You don't need an online calculator.

Power = (Voltage Squared) / (Resistance)

Idris

---

{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.

Thank you @Diggrr and @Moriquendi. That works like magic. Or science. Best regards ...

---

New browser from the creator of Opera: [vivaldi.com]

Unfortunately Moriquendi, I have a factory full of part numbers sharing space with my formula storage.