Frequently asked questions
How do I check a cable for voltage drop?
Put the cable size, length and current into the voltage drop calculator. Local rules, such as the Saudi Building Code or DEWA's regulations, may set their own limits.
How hot does it really feel outside?
The heat index calculator combines temperature and humidity. On a humid day in Jeddah or Dubai, the feels-like figure can be far above the thermometer.
Which units can I use?
SI units throughout, plus the US ones people actually use, such as psi, horsepower and °F. Every field shows its unit.
Can I check my chemistry homework?
Yes. The molar mass and molarity calculators show each step, so you can see where an answer came from.
How do I read resistor colour bands?
Pick the colours in order in the resistor colour code calculator and it gives you the value and tolerance.
Is anything I enter sent or stored?
No. Every calculation runs in your browser, and nothing you type is sent to us or saved.