Construction Unit Converter
Convert the units construction actually uses — feet and inches to metres, square feet to square metres, cubic yards to cubic metres, pounds to kilograms — with factors that are exact by international definition, and print the quick-reference chart for the job box.
Convert a measurement
Example: a 12 ft wall line is 3.6576 m; a 5 ft 6 in counter height is 1.6764 m. Results show 6 significant digits; the arithmetic underneath is exact.
Conversions here are unit arithmetic on the numbers you enter — verify dimensions on site, and leave structural adequacy, code compliance, and engineering to a qualified professional.
Exact factors, honestly rounded
Every factor on this page traces to two definitions the US National Bureau of Standards adopted on 1 July 1959: 1 yd = 0.9144 m and 1 lb = 0.45359237 kg, both exact. From those, 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 sq ft = 0.09290304 m², and 1 cu ft = 0.028316846592 m³ follow exactly. The converter multiplies by one whole-number factor and divides by another — nothing else — so 12 ft is exactly 3.6576 m and an 80 lb bag is exactly 36.2873896 kg, shown as 36.2874 kg at 6 significant digits. The methodology page describes the precision contract shared by every tool on this site.
Cubic yards on one side of the ocean, cubic metres on the other
US ready-mix plants sell concrete by the cubic yard — a typical mixer truck carries 9 to 11 of them — while suppliers in metric countries price and batch by the cubic metre. The two differ by nearly a third: 1.30795 cu yd fit in a cubic metre, and a 5 cu yd order is 3.82277 m³. Bagged material splits the same way: US concrete mix comes in 40, 50, 60, and 80 lb bags, while metric markets sell 25 kg and 30 kg bags — so an 80 lb bag (36.2874 kg) sits between the two metric sizes rather than matching either. Lumber tells the story in length: the 8 ft stud is 2.4384 m, which is why metric framing stock is cut at 2.4 m. When a quote crosses systems, convert the quantity first and only then compare prices.
The estimators already speak both systems
Every calculator on this site has an imperial/metric toggle that uses these same exact factors, so you rarely need to convert by hand before estimating. Measure in whichever system your tape uses and go straight to the square footage, volume, linear feet, feet & inches, stair, roof pitch, board foot, concrete slab, concrete bag, brick, concrete block, concrete footing, concrete column, post hole concrete, rebar, paver, gravel, topsoil, mulch, sand, sod, paint, drywall, flooring, tile, wallpaper, insulation, roofing shingle, siding, fence, or deck material calculator — this page is for the moments in between: reading a metric drawing with an imperial tape, comparing a tonne price to a ton price, or translating a materials list for a supplier in the other system.
Frequently asked questions
Why does this page call the conversions "exact"?
Because they are exact by definition, not by measurement. The 1959 international yard-and-pound agreement, adopted by the US National Bureau of Standards, fixed 1 yd = 0.9144 m and 1 lb = 0.45359237 kg exactly — which makes 1 ft = 0.3048 m and 1 in = 25.4 mm exact too. Every factor on this page derives from those definitions; the only rounding is in the displayed digits (6 significant figures).
What is the difference between a ton and a tonne?
A US short ton is 2,000 lb = 907.18474 kg exactly. A metric tonne is 1,000 kg ≈ 2,204.62 lb — about 10% heavier. US aggregate suppliers quote short tons; metric-world suppliers quote tonnes. When a quote just says "ton", ask which one before comparing prices.
How do I convert a concrete order from cubic yards to cubic metres?
Multiply by 0.764554857984 (exactly 27 cu ft × 0.3048³). A 5 cu yd US order is 3.82277 m³; going the other way, 1 m³ is 1.30795 cu yd. Note that ordering increments differ too: US plants commonly sell by the quarter or half yard, metric plants by fractions of a cubic metre.
Is a "yard" of concrete the same yard as on a tape measure?
No — trade shorthand drops the "cubic". A "yard" of concrete, gravel, or mulch is a cubic yard (27 cubic feet), a volume. The yard on a tape measure is 3 feet, a length. This converter keeps them in separate categories so the two can never be mixed up.
Why do the calculators on this site work in feet internally?
Every estimator on this site computes in canonical units — feet, square feet, cubic feet — and converts metric entries in and out with the same exact factors used here. Both unit systems produce byte-for-byte identical math; only the presentation changes. That is also why this converter agrees with every on-page toggle.
Printable quick-reference chart
Common construction conversions at 6 significant digits, computed by the same engine as the converter above. The print button strips the navigation, sidebar, and form so the chart comes out clean on one sheet.
Length
| This much | Equals |
|---|---|
| 1 in | 25.4 mm = 2.54 cm |
| 1 ft | 0.3048 m = 30.48 cm |
| 1 yd | 0.9144 m |
| 8 ft (stud / sheet length) | 2.4384 m |
| 10 ft | 3.048 m |
| 100 ft | 30.48 m |
| 1 m | 3.28084 ft = 39.3701 in |
| 1 cm | 0.393701 in |
Area
| This much | Equals |
|---|---|
| 1 sq ft | 0.092903 m² |
| 1 sq yd | 9 sq ft = 0.836127 m² |
| 32 sq ft (4×8 sheet) | 2.9729 m² |
| 100 sq ft (1 roofing square) | 9.2903 m² |
| 1,000 sq ft | 92.903 m² |
| 1 m² | 10.7639 sq ft |
Volume
| This much | Equals |
|---|---|
| 1 cu ft | 0.0283168 m³ = 28.3168 L |
| 1 cu yd | 27 cu ft = 0.764555 m³ |
| 5 cu yd (typical slab order) | 3.82277 m³ |
| 10 cu yd (full mixer truck) | 7.64555 m³ |
| 1 m³ | 1.30795 cu yd = 35.3147 cu ft |
| 1 L | 0.0353147 cu ft |
Weight
| This much | Equals |
|---|---|
| 1 lb | 0.453592 kg |
| 40 lb bag | 18.1437 kg |
| 50 lb bag | 22.6796 kg |
| 60 lb bag | 27.2155 kg |
| 80 lb bag | 36.2874 kg |
| 25 kg bag | 55.1156 lb |
| 30 kg bag | 66.1387 lb |
| 1 kg | 2.20462 lb |
| 1 US ton (short) | 2,000 lb = 907.185 kg |
| 1 tonne (metric) | 1,000 kg = 2,204.62 lb |
Factors are exact by the 1959 international yard-and-pound definitions; values are rounded to 6 significant digits for display. ConstructionCalculations.net/unit-converter/
Nothing you type leaves your device. These are unit conversions and quantity estimates only — no structural adequacy, code compliance, or engineering judgment; verify dimensions and local code with a professional. See how every tool is built and tested on the methodology page.