Shard Tools

Unit Conversion Tools for Everyday Measurements

By Roshan · Updated

A conversion is only useful when the input unit, output unit, and rounding are clear. Use this guide to choose the right converter and check the result before you rely on it.

Convert PSI to barConvert km/h to mphConvert litres to gallonsConvert gallons to litresConvert kilojoules to caloriesConvert millilitres to cupsConvert tablespoons to mlConvert MB to KBInspect local processing

Write the unit convention beside the result

A numerical conversion needs the source's unit definition as well as its label. For example, US and imperial gallons represent different volumes, while a cup may mean 240 ml or 250 ml depending on context. Read the tool's stated convention before converting a recipe, specification or order, and record that convention if someone else will reuse the number.

Convert with full precision, then round once for the destination. Repeatedly converting rounded numbers can create discrepancies that look like conflicting formulas. Keep quantities separate: centimetres measure length, square centimetres measure area, and cubic centimetres measure volume. Applying a linear factor once to an area or volume would be wrong. When an output seems surprising, check the input magnitude and whether the original uses a fraction or a decimal before assuming the arithmetic is at fault.

Pressure and speed conversions

Use PSI to bar or bar to PSI when reading tyre gauges, pumps, HVAC equipment, or technical specifications that use different pressure units. For a quick check, 32 PSI is about 2.21 bar, but use the exact result for a specification or setting.

Use km/h to mph or mph to km/h for road signs, vehicle displays, cycling computers, and travel. The result is a reading aid; follow the legal unit and value shown on the local sign or document.

Volume, weight, and length

Volume conversions such as litres to gallons, gallons to litres, millilitres to cups, and tablespoons to millilitres are useful for recipes, packaging, and product specifications. Check whether the source uses US or Imperial units because a gallon is not the same size in both systems.

For weight and length, choose the converter that matches the original measurement rather than guessing from the number alone. Keep the original value beside the converted result when copying it into a form or spreadsheet.

Check rounding and privacy

Most practical conversions are rounded for display, while the calculation uses a more precise factor. If a result is being used for engineering, medical, legal, or financial work, confirm the required precision and the source unit before using it.

Shard Tools performs these arithmetic conversions in the browser. The number you enter is not uploaded or stored, and the result is available immediately without an account.