Free tool
Metric ↔ imperial converter
Convert length, area, weight, and temperature between metric and imperial units. Type a value, pick a unit, and every equivalent updates instantly. Free, and nothing leaves your browser.
| Millimetres (mm) | 1,000 |
| Centimetres (cm) | 100 |
| Metres (m) | 1 |
| Kilometres (km) | 0.001 |
| Inches (in) | 39.370079 |
| Feet (ft) | 3.28084 |
| Yards (yd) | 1.093613 |
| Miles (mi) | 6.2137e-4 |
Metric and imperial, side by side
AV and IT installs live in two measurement worlds at once: gear is spec'd in millimetres and kilograms, sites are described in feet and inches, and clients switch between them without warning. This converter keeps both straight so a cable run, a rack weight, or a room dimension never gets lost in translation.
Common conversions
- 1 inch = 25.4 mm · 1 foot = 0.3048 m · 1 metre = 3.281 ft
- 1 kg = 2.205 lb · 1 lb = 0.4536 kg
- °F = °C × 9/5 + 32 · °C = (°F − 32) × 5/9
Working on a real project? Avitly stores every length canonically and shows it in metric or imperial with one toggle, so your whole plan, quote, and offer stay consistent, with no manual conversion required.
Common questions
How many millimetres are in an inch?
Exactly 25.4 mm. That figure is a definition rather than a measurement, agreed internationally in 1959, so conversions between inch and metric lengths are exact and not rounded.
What is a rack unit in millimetres?
One rack unit, written 1U, is 1.75 inches or 44.45 mm. A standard 19 inch rack has 482.6 mm of external width with a 450 mm opening between rails. A 42U rack therefore has 1866.9 mm of usable height, which is why full-height racks are quoted around 2 metres once you include the plinth and top.
How do I convert cable length from feet to metres?
Divide by 3.2808, or multiply by 0.3048. A 100 ft drum is 30.48 m. When you are ordering cable, round up rather than down and add slack for terminations and service loops, since a run that is 200 mm short costs a whole new pull.
Why do AV spec sheets mix metric and imperial?
Rack hardware, screen sizes, and connector standards came from US manufacturing and stayed in inches, while construction drawings outside the US are metric. So you routinely spec a 19 inch rack for a room dimensioned in millimetres. The mixture is historical, not logical, and it is the usual source of ordering mistakes.
How do I convert a display's diagonal to width and height?
Multiply the diagonal by 0.872 for width and 0.490 for height on a 16:9 panel. A 75 inch display is therefore about 65.4 by 36.8 inches, or 1661 by 934 mm. Add bezel and mount depth before you commit to a niche or a wall recess.
What is the difference between weight in kg and lb for mounting?
One kilogram is 2.2046 pounds. Mount and bracket ratings are published in whichever unit the manufacturer's home market uses, so always convert before comparing a display's mass to a bracket's rating, and keep a safety margin rather than sizing to the exact limit.
Design it once. Sell it, install it, service it.
Avitly runs the whole install off one floor plan: quote, client-signed offer, bill of materials, rack layout, then device credentials and tickets after handover. Presales to maintenance, no re-entry.
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