How to convert miles to kilometres in a spreadsheet
Grid by Zaweba's CONVERT function turns miles into kilometres, pounds into kilograms and many more units using a built-in unit table, free and offline.
The CONVERT function handles it. In Grid by Zaweba, =CONVERT(A2,"mi","km") turns the miles in A2 into kilometres, and the same function converts weights, temperatures, volumes, areas, speeds and more from a built-in unit table. You never need to look up a conversion factor or type it in yourself.
How CONVERT works
It takes three arguments: the number, the unit it's in, and the unit you want. The units are short text codes in quotes, the same codes other spreadsheets use. Miles are "mi" and kilometres "km", pounds are "lbm" and kilograms "kg", degrees Celsius are "C" and Fahrenheit "F". If the two units measure different things, such as miles and kilograms, the result is #N/A, which is a useful safety net.
Unit codes are case-sensitive, because some letters mean different things in upper and lower case. If a conversion that ought to work returns an error, check the capitals first.
Converting a column of values
Put your values in a column with a heading that says what unit they're in. In the next column, type =CONVERT( then click the first value, add the from and to codes in quotes, and press Enter. Double-click the fill handle to copy the formula down the whole column.
A tidier approach is to put the unit codes in two cells at the top, say B1 and C1, and point the formula at them with dollar signs to fix the references. F4 cycles the dollar signs while you're editing. Change the codes in those cells and the whole column converts to different units, which is handy for a recipe or a running log that some people read in miles and others in kilometres.
Metric prefixes
Many units accept a metric prefix written before the code. Kilo, centi and milli work as you'd expect, so the same function covers grams to kilograms, or metres to millimetres. That saves you multiplying by powers of ten by hand.
Everyday uses
Travel and fitness: miles to kilometres, or speeds between miles per hour and kilometres per hour, for a route planner or a training log.
Cooking and shopping: ounces to grams, pints to litres, for a recipe sheet or comparing prices on packs labelled in different units.
Home projects: feet and inches to metres, or square feet to square metres when working out paint or flooring.
Weather and science: Fahrenheit to Celsius, and other temperature scales, where a fixed multiplier wouldn't work because the scales start in different places.
Neat results
Conversions often produce long decimals. Wrap CONVERT in ROUND to a sensible number of places, or keep the full value and set a number format that shows two decimal places. A custom number format can add the unit to the display, so 12.5 shows as 12.5 km while staying a number you can add up.
Where CONVERT lives
CONVERT is part of Grid's Engineering family of 54 functions, along with base conversions such as BIN2DEC, bit functions and complex numbers. You'll find it in Insert Function (fx) under Engineering, with a description of each argument and a live result as you fill them in, and autocomplete offers it as soon as you start typing.
One function and a pair of codes is all it takes, and because Grid by Zaweba works offline, the conversion table is always to hand, with no website to visit.
