Home and Garden Calculators
Plan a project without over-ordering. Work out how much paint, tile, concrete, mulch, soil or gravel you need from a few measurements, with results that update as you type.
Paint Calculator
Work out litres of paint and 2.5 litre tins from room size, coats and coverage.
Open calculator Plot No. 63 · Home & GardenTile Calculator
Find how many tiles to buy from the area and tile size, including a waste allowance.
Open calculator Plot No. 64 · Home & GardenConcrete Calculator
Estimate concrete volume and 25 kg bags for a slab, with a 10 percent waste buffer.
Open calculator Plot No. 65 · Home & GardenMulch Calculator
Convert bed size and depth into mulch volume, litres, 50 litre bags and cubic yards.
Open calculator Plot No. 66 · Home & GardenRaised Bed Soil Calculator
Work out the soil to fill a raised bed in cubic metres, litres and 50 litre bags.
Open calculator Plot No. 67 · Home & GardenGravel Calculator
Estimate gravel by tonnes and bulk bags from area, depth and stone density.
Open calculatorWhich home and garden calculator do you need?
Surfaces first, then anything you fill.
| What you want to do | Calculator | What it gives you |
|---|---|---|
| Buy paint for a room | Paint Calculator | Litres needed and the number of 2.5 litre tins, allowing for doors and windows |
| Order tiles for a floor or wall | Tile Calculator | Tile count for the area with wastage added |
| Pour a slab, base or path | Concrete Calculator | Slab volume in cubic metres and the number of 25 kg bags |
| Mulch a bed or border | Mulch Calculator | Volume and bag count at your chosen spread depth |
| Lay gravel on a drive or path | Gravel Calculator | Volume and tonnage at your depth and bulk density |
| Fill a raised bed with soil or compost | Raised Bed Soil Calculator | Litres of growing medium and the number of 50 litre bags |
What the home and garden calculators do
Every calculator in this plot answers one version of the same question: how much material do I need to buy. Paint and tiles cover a surface, so they work from area. Concrete, mulch, gravel and raised bed soil fill a volume, so they work from area multiplied by a depth. Get the depth wrong and the order is wrong by the same proportion, which is why each tool asks for it separately instead of hiding it in an assumption.
The answers are deliberately given in the units the shop sells in, not just in cubic metres. Paint comes back as litres and as a count of 2.5 litre tins. Tiles come back as a tile count with wastage already added. Raised bed soil comes back as 50 litre bags. That is the number you actually need at the checkout, and it is where rounding matters: half a tin does not exist, so the sensible answer is always the next whole unit up.
Two habits save more money than any calculator. Measure the space twice and write it down, because a 10 centimetre error over a long wall is a whole extra tin. And buy the wastage rather than economising on it, because a second delivery of gravel or a second batch of tiles from a different production run costs far more in time and mismatch than the surplus does.
The defaults each home calculator starts from
Every one of these is editable, but they are the figures the tools land on, and they are the ones worth checking against your own product before you order. A default that is close for a typical job can be badly wrong for an unusual one.
| Job | Default | Why that figure |
|---|---|---|
| Wall paint | 11 square metres per litre | Mid-range for matt emulsion, which tins usually quote at 10 to 13 |
| Tiles | 30 cm tiles with 10 percent wastage | Covers cut tiles at the edges and the occasional breakage |
| Concrete | 10 cm depth | A common depth for a shed base, path or light-duty slab |
| Bark mulch | 7 cm spread depth | Deep enough to suppress weeds without smothering plants |
| Gravel | 5 cm depth at 1.6 tonnes per cubic metre | A standard decorative topping, at the usual bulk density for gravel |
| Raised bed soil | 30 cm bed height, 50 litre bags | Matches a typical two-plank bed and the standard compost bag size |
Paint coverage is the default most worth changing. Bare plaster, textured walls and a dark colour going over a light one all drink noticeably more than 11 square metres per litre, and the figure printed on your specific tin beats any general rule. For gravel, bulk density varies with stone size and how wet it is, so treat the tonnage as an order guide rather than a precise weight.
Home & Garden guides
How Much Does a Litre of Paint Cover?
A litre of emulsion covers about 12 square metres per coat. Coverage by paint type, why bare plaster halves it, and how to convert area into tins.
How Many Tiles Do I Need for a Bathroom?
Measure each wall and the floor in square metres, add 10 percent waste, then divide by the coverage per box. Worked bathroom example and the cuts to expect.
How Much Gravel Do I Need for a Driveway?
Length x width x depth in metres gives cubic metres; multiply by 1.6 for tonnes. Driveway depths, the sub-base you also need, and a worked example.
Best free tile calculator (no signup)
Which free tile calculator to use, with an honest table comparing Calc Garden, Omni Calculator, Calculator.net and Topps Tiles on waste allowance, grout gaps, boxes and cost.
Free Dulux paint calculator alternative
How Calc Garden's free, no-signup paint calculator compares to the Dulux paint calculator, with an honest feature table and where each one wins.
How Much Soil for a Raised Bed? (UK Bag Guide)
Work out raised bed soil: length x width x depth in metres, then convert to litres and 50L bags. Worked example plus the ideal topsoil and compost mix.
How Much Concrete for a Shed Base? UK Guide
Work out concrete for a shed base: length x width x 0.1 m for 100 mm, plus 10 percent waste. Worked example, the C20 1:2:4 mix, and bags vs ready-mix.
Browse every Calc Garden guide.
Frequently asked questions
How much paint do I need for one room?
Measure the perimeter, which is twice the length plus width, multiply by the wall height, then subtract roughly 1.8 square metres for each door or window. Multiply by the number of coats and divide by the coverage on the tin. The paint calculator does exactly this and converts the litres into whole tins.
How deep should mulch or gravel go?
Around 7 centimetres of bark mulch is enough to suppress weeds while still letting water through, and about 5 centimetres of decorative gravel gives coverage without being hard to walk on. A drive that takes vehicle traffic needs considerably more depth and a proper sub-base, which is a groundwork question rather than a volume one.
Should I order extra?
Yes, and the calculators already round up to whole tins, bags or tiles. Ten percent wastage on tiles is standard because of edge cuts, and a spare tin of paint from the same batch is worth having for touch-ups later, since colour can shift slightly between production runs.