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Slope calculator
A slope in %, degrees and 1 in X, checked against UK guidance.Cubic metres to tonnes
The tonnes for a volume, or the other way round, by material.Concrete calculator
The volume in cubic metres and the bags of concrete to buy.Pool volume calculator
The water volume in m³ and litres, and the filling time.Stair calculator
Risers, rise, going and the Approved Document K checks.Screed calculator
Bags of screed or levelling compound for your floor area.
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Measuring & setting out
6 toolsSlope calculator
A slope in %, degrees and 1 in X, checked against UK guidance.Pool volume calculator
The water volume in m³ and litres, and the filling time.Stair calculator
Risers, rise, going and the Approved Document K checks.Mitre angle calculator
Mitre cuts, square corners and roof pitch in degrees.Roof area calculator
Roof area and number of tiles for the chosen tile.Wall area calculator
Wall, floor and ceiling areas in m², openings taken off.
Brickwork & concrete
4 toolsDecorating & finishing
3 toolsHeating, energy & electrics
4 toolsBuilding calculations that cite their rule
Brikalo brings together 17 free calculators for building and DIY jobs: the fall on a waste pipe, the steps in a staircase, the concrete for a slab, the bags of cement, the litres of paint for a room. Each page does one job and puts it at the top of the screen. Below, it explains how the result is worked out, with an example done by hand, and which document the rule comes from.
UK regulations and manufacturers’ data sheets
Every figure on a building job comes from a document. In England, the Building Regulations are explained in the Approved Documents: Part K covers stairs and ramps, Part H drainage, Part F ventilation, Part L insulation and energy use, and Part P electrical safety in homes, with wiring to BS 7671. Scotland, Wales and Northern Ireland publish their own guidance, so where a rule differs the page says which nation it applies to. Mortar mixes, the coverage of a paint or how much tile adhesive you need come from the manufacturer’s data sheet.
Every page lists its sources with a link. Where a rule changes from one country to another, the English version applies the UK rule and says so. A French value is never presented as a UK requirement, and a value with no source that can be checked is not shown: the calculator asks for the figure on your data sheet instead. The details are in our editorial method.
Your measurements stay with you
Calculations run in your browser. The measurements you type are not sent to any server. There is no account to create: your result history and favourite calculators are kept in this device’s local storage, and you can clear them whenever you like.
By stage of the job
Measuring and setting out.
- Work out a slope as a percentage or in degrees for a roof, a drain or a ramp.
- Calculate a staircase: number of steps, rise and going.
- Work out the area of a room in square metres, walls included, doors and windows taken off.
- Find the mitre angle for skirting and frames.
- Work out the area of a roof from its pitch.
- Calculate the volume of water in a pool.
Brickwork and concrete.
- How many cubic metres of concrete for a slab, a footing or a post, and how many bags of cement.
- Convert cubic metres to tonnes when ordering loose gravel or sand.
- Blocks and mortar for a wall.
- Screed and self-levelling compound.
Decorating and finishing.
Heating, energy and electrics.
- The thermal resistance of insulation.
- Air conditioner capacity.
- Ventilation airflow for a home.
- How many kWh an appliance uses.
How to read a result
All measurements are metric, and numbers use a decimal point: 2.4 m³, 1,250 kg. Below each result you will find the working with the values used, so you can check it on a calculator. “Copy link to this result” reopens the same calculation with the same values, on your phone on site or at the builders’ merchant.
What a calculator does not replace
A result is a quantity or a reminder of the rule: it helps you prepare an order, compare quotes or check a measurement. It does not replace a structural engineer for foundations, floors or a roof, Building Control approval where the work needs it, a registered electrician for notifiable electrical work, or the instructions of the manufacturer whose product you are using.
Frequently asked questions
Are Brikalo’s calculators free?
Yes, all of them, with no sign-up and no paid tier. Ads may appear below the calculators to pay for the site; they have no effect on the calculations or the text.
Are my measurements sent anywhere?
No. Calculations happen on your device. Only your settings, history and favourites are kept, in your browser’s local storage.
Where do the mixes and coverage rates come from?
From manufacturers’ data sheets and the documents cited on each page. Where a coverage rate depends on the product, the calculator lets you enter the one on your data sheet.
Do the pages follow UK rules?
Where the rule depends on the country, yes: the English page cites the UK document (an Approved Document, BS 7671…) and shows no value if there is no open UK source for it. Geometric formulas, such as a slope, an area or a volume, are the same everywhere.
Does a result replace a professional?
No. A quantity or a reminder of the rule helps you plan a job and a budget. For structural work or electrical work, talk to a structural engineer, Building Control or a registered electrician.
I have spotted a mistake. What should I do?
Write to us through the contact page with the calculator, the values you entered and the result you expected. A confirmed error is corrected and the page’s update date changes.