Concrete Calculator
Volume, premix bags and weight for slabs, footings, columns and solid stairs, in cubic metres and cubic yards, with a dimensioned drawing of the shape you picked and an optional rebar estimate.
Shape and dimensions
Volume
1.200 m³
Cubic yards
1.570 yd³
With 5% extra
1.260 m³
Weight
3024 kg
Premix bags
Bag counts use the yield printed on typical product data sheets. Mixing by hand for anything bigger than about 1 m³ is hard work — past that, ready-mix delivery is usually cheaper.
| Bag | Yield | Bags needed | Total weight |
|---|---|---|---|
| 20 kg bag | 0.0100 m³ (0.35 ft³) | 127 | 2540 kg |
| 25 kg bag | 0.0125 m³ (0.44 ft³) | 101 | 2525 kg |
| 40 kg bag | 0.0200 m³ (0.71 ft³) | 64 | 2560 kg |
| 40 lb bag | 0.0085 m³ (0.30 ft³) | 149 | 2703 kg |
| 60 lb bag | 0.0127 m³ (0.45 ft³) | 100 | 2722 kg |
| 80 lb bag | 0.0170 m³ (0.60 ft³) | 75 | 2722 kg |
Order a little more than the calculation: concrete is lost to spillage, uneven sub-base and the inch or two left in the mixer, and a short pour that sets is far more expensive than a spare bag. For a ready-mix truck, round up to the next quarter of a cubic yard (or 0.1 m³).
Dimensioned drawing
The shape at scale with the dimensions you entered.
About this tool
Slabs and pads are length × width × depth; a round column is πr²h; a square column is side²h; a solid stair is the sum of one box per step (width × going × riser × n(n+1)/2). Results are given in cubic metres and cubic yards with the bag counts for common 20/25/40 kg and 40/60/80 lb premix, plus an optional rebar estimate from bar size, spacing and cover. Everything runs in your browser; nothing is uploaded.
- 100% free — no account needed
- Runs in your browser
- Nothing is uploaded
Frequently asked questions
Is Concrete Calculator really free?
Yes. Concrete Calculator is completely free on PureBrowser — every feature, with no account, no trial, and no credit card.
Does Concrete Calculator upload my data?
No. Concrete Calculator runs entirely inside your browser, so anything you type, paste, or open stays on your own device.
Do I need to sign up or install anything?
Neither. There is no account and nothing to download — open the page and Concrete Calculator is ready to use on desktop or mobile.
Does Concrete Calculator work offline?
Once the page has loaded, yes. All of the processing happens locally in your browser, so it keeps working without a connection.
More utility tools
Password Strength Checker
Score your password strength and generate stronger ones.
Password Generator
Generate strong random passwords with configurable length and character sets.
Decision Maker
Let the tool randomly pick from your list of options.
Yes or No Wheel
Spin a wheel for a random yes or no answer.
Discord Timestamp Generator
Pick a date and time to generate Discord timestamp tags with live preview and one-click copy.
Discord Embed Builder
Design Discord embeds with live preview — copy JSON for bots, webhooks, and Discord.js.