I don’t know who decided that we need inches AND centimetres, pounds AND kilograms, Fahrenheit AND Celsius — but they clearly didn’t think about people who shop online from other countries. Half my week is spent Googling stuff like “24 inches in cm” because some American website listed a monitor size in inches and I can’t picture what 24 inches looks like.
My brain works in metric. I think in centimetres, kilograms, litres, Celsius. But the internet is mostly American, so every product listing, recipe, fitness video, and weather article throws imperial units at me. I got sick of the back-and-forth Googling, so I made a unit converter that handles all of it in one place.
The conversion I mess up the most
Temperature. Every single time. The formula is subtract 32, multiply by 5, divide by 9. Sounds simple until you’re actually doing it in your head while someone waits for your answer.
My cousin lives in Texas and he’ll text me things like “bro it’s 108 today.” And I have to stop and do the maths. 108 minus 32 is 76. Times 5 is 380. Divided by 9 is… I usually pull out my phone at this point. (It’s 42.2°C. Basically Lahore in July. I could’ve just said that.)
The annoying part is Fahrenheit to Celsius has that weird subtract-then-multiply formula. It’s not a clean conversion like cm to inches where you just multiply by one number. There’s always an extra step and that’s where I make mistakes.
Rounding has cost me actual money
I’ve told this story before but it still annoys me. I was packing for a flight, checked my bag weight in pounds, and did a rough “divide by 2.2” to get kilograms. Got to the airport, bag was over the limit. Paid the overweight fee. All because 1 kg is 2.20462 pounds, not 2.2 — and when you multiply that small error by 23 kg it adds up.
Now imagine doing that with bigger numbers or chained conversions. Say you need to convert square feet to square metres. You might think “well 1 foot is 0.3048 metres, so I’ll just multiply by 0.3048.” Nope. That’s the linear conversion. For area you need to square the factor — multiply by 0.0929. I got this wrong helping someone measure their room and told them they had way more space than they actually did. Not the end of the world, but embarrassing when someone checks your maths.
The real problem
The thing is, unit conversion is just multiplication. It’s not hard maths. But who actually remembers any of the numbers? I know 1 inch is 2.54 cm because I’ve looked it up a thousand times. Everything else — miles to km, pounds to kg, gallons to litres — I have to look up every single time. And if I round to make the mental maths easier, I end up with wrong answers. There’s no winning.
What I keep converting
Inches to cm. All the time. Online shopping — monitor sizes, desk dimensions, phone screens. Every American product page uses inches and I need cm to know if something fits.
Fahrenheit to Celsius. Weather, cooking temps, those random American tweets about heatwaves. “It’s 95°F outside” means nothing to me until I know it’s 35°C.
Miles to km. When someone says “it’s about 50 miles away” I just stare blankly. 50 miles is 80 km. That I can work with. Also speed limits — 70 mph sounds fast until you realise it’s 112 km/h which is just normal motorway speed.
The converter does all of these. Length, weight, temperature, area, volume — pick what you’re converting from, pick what you’re converting to, type the number. No formulas, no rounding, no five separate Google searches. I built it because I was the person who needed it most.