Convertly

Convertly converts units and does the small sums you keep reaching for a calculator to do. It works with the device offline, asks for no permissions at all, and keeps everything on your phone. FOURTEEN CATEGORIES Length, Weight, Temperature, Volume, Area, Speed, Time, Data, Pressure, Energy, Fuel Economy, Angle, Cooking and Shoe Size. Type a number once and read it in every unit of the category in the list underneath, or pick just the pair you need. Temperature uses real formulas rather than a multiplier, and tells you when a value is below absolute zero instead of printing nonsense. Fuel Economy handles the fact that L/100 km runs the opposite way to MPG, and supports both the US and the UK gallon. Data lists decimal units (MB) and binary units (MiB) side by side, which is why a phone and a shop rarely agree about the size of a drive. FAVORITES AND HISTORY Pin the pairs you use — km to miles, kilograms to pounds, Celsius to Fahrenheit — and they sit on the first screen. The last fifty conversions are remembered with the numbers you entered, and tapping one runs it again. CALCULATORS Percentage: X% of Y, X is what percent of Y, and the change from A to B. Tip & Split: the bill, the tip, the number of people, and rounding that applies to each person's share so the total on the table actually matches. Discount: the final price, the money saved, and a second discount applied the way shops apply it — to the already reduced price, not added to the first. Ratio: a : b = c : x. Date Difference: days, weeks, months and workdays between two dates, plus adding days to a date. MADE TO BE READ Big numerals, one-handed layout, a light and a dark theme, thousands grouping, a choice of decimal separator and precision from zero to six places. Trailing zeros are dropped so a result never looks longer than it is. ACCURATE ON PURPOSE Conversion factors are the exact published definitions and are checked by automated tests against reference values. Shoe sizes are the one exception and the app says so where it shows them: they are a table, and brands differ. No currency rates — those need a live connection, and this app never goes online. No account, no ads, no analytics, no permissions.