Concrete Calculator: Slab, Mix

How much concrete do you need? Enter length, width and thickness – ConcreteCalc shows the volume, bags, weight and mixer truck loads in seconds. 13 calculators, works offline, no ads.

13 CALCULATORS FOR YOUR PROJECT

• Concrete slab: concrete for floor slabs from length, width and thickness.
• Footing: rectangular strip and pad footings, one or many.
• Column / round footing: volume for circular foundations and columns.
• Fence post holes: concrete per hole and number of 80 lb or 25 kg bags, minus the post.
• Concrete wall: volume and formwork area for walls.
• Concrete stairs: concrete for solid steps on the ground from number of steps, step height and depth.
• Rebar for slabs: bar count, total length and weight for a bar grid, #3–#6 or Ø 8–16 mm.
• Concrete bags: number of bags from volume and yield per bag, rounded up.
• Concrete mix: cement, sand, gravel and water for site-mixed concrete at 1:1.5:3, 1:2:4 or 1:3:6 – including cement bags.
• Floor screed: dry mix and bags from area, thickness and the consumption printed on the bag.
• Gravel / crushed stone: volume and weight in tonnes or US tons for sand, gravel, crushed stone or chippings.
• Bricks / blocks: block quantity from wall and block size, optional joint width.
• Material costs: costs for ready-mix or bagged concrete with your own prices.

WEIGHT, MIXER TRUCKS AND RESERVE

Concrete results show the weight and the mixer truck loads you need. Choose 0, 5, 10 or 15 percent reserve; results show the base quantity and totals including reserve. Send a concrete result straight to the bags, mix or cost calculator.

EASY ON SITE

Millimetres, centimetres and metres as well as inches, feet and yards are supported. Units follow your region automatically, or choose metric or imperial in Settings: results show cubic yards and cubic feet alongside cubic metres, and volumes can be entered in m³, litres, yd³ or ft³. In US units, bags show 40, 60 or 80 lb, cement 94 lb, weights lb and US tons, and mixer trucks 10 yd³. Comma and point both work for decimals. Share your calculation through the Android share menu.

Choose English, German, Spanish, French, Italian or Portuguese, with light and dark mode. All calculators work offline. No account required.

CONCRETECALC PRO

All calculators are free and without ads. Pro is a one-time in-app purchase, no subscription:
• Projects: save calculations, name them and reopen them later
• PDF export: share a single result or a whole project as a material list
If you want to support development, you can leave an optional tip in Settings. Projects stay on your device only. Google Play purchases need an internet connection.

ConcreteCalc provides estimates. Check results, material yield and requirements before ordering or building. Mixes are guide values for site-mixed concrete; for load-bearing parts follow your structural engineer's specification. Rebar results are quantities only, no structural or reinforcement design; material costs exclude delivery and labour.

Recent changes:
No more ads: all calculators are free and ad-free. Pro (projects and PDF export) remains a one-time purchase. New: optional tip in Settings. Settings reorganized into clear sections, new gear icon.