Unit Conversion Calculator
The conversions metal buyers actually use — with both directions computed at once from exact SI definitions, not rounded trade approximations.
Both directions are shown: the forward conversion, and the same figure converted back the other way. All factors are exact SI definitions — 1 in = 25.4 mm, 1 lb = 0.45359237 kg, 1 ft = 0.3048 m.
The Factors, Exactly
| Pair | Factor | Definition |
|---|---|---|
| mm ↔ in | 1 in = 25.4 mm | Exact since the 1959 international yard & pound agreement |
| m ↔ ft | 1 ft = 0.3048 m | Exact, same agreement |
| kg ↔ t | 1 t = 1000 kg | Exact, metric definition |
| kg ↔ lb | 1 lb = 0.45359237 kg | Exact, same agreement |
| kg/m ↔ lb/ft | 1 lb/ft = 1.488163944 kg/m | Derived: 0.45359237 kg ÷ 0.3048 m |
| MPa ↔ psi | 1 psi = 6.894757293168 kPa | Derived: 4.4482216152605 N ÷ 645.16 mm² |
Where a trade rounding exists (e.g. "1 kg ≈ 2.2 lb"), this calculator shows the exact conversion; the rounding belongs in conversation, not in a datasheet.
Converting an Imperial Enquiry?
Send the sizes in any unit — the desk quotes in metric, imperial, or both.