How to estimate a room renovation
Most room makeovers come down to walls, floor and time. This room renovation cost calculator prices the paint for your wall area, the flooring for your floor area, and the labour days to do it, at budget, mid-range or premium quality — then shows materials and labour separately, because that split is where quotes differ most.
Walls
Paint = wall area × coats ÷ 10 m² per litre. A typical double bedroom has around 60 m² of wall once you multiply the perimeter by the ceiling height. Two coats is 12 litres.
Floor
Flooring = floor area × price per m² for your quality tier. Measure length × width; add a little for cuts if the room has alcoves or bays.
Labour
Labour = days on site × day rate. A decorator and a flooring fitter charging around £220 a day will often spend four days on a room including preparation.
Worked example: a double bedroom
60 m² of wall, two coats, a 16 m² floor and four days of labour.
| Quality | Paint (12 L) | Flooring (16 m²) | Labour (4 days) | Total |
|---|---|---|---|---|
| Budget | £144 | £224 | £880 | £1,248 |
| Mid-range | £288 | £448 | £880 | £1,616 |
| Premium | £492 | £832 | £880 | £2,204 |
Labour is more than half the mid-range total. Doing the work yourself leaves the materials — but allow for tools, dust sheets, filler and your own time.
Why real quotes come in higher
Preparation
Filling cracks, sanding, masking, removing old wallpaper and lifting the old floor all take time before the visible work starts. On an older house, preparation can take as long as the painting.
Woodwork, ceilings and extras
Skirting boards, door frames, radiators and ceilings take extra paint and labour. Use the paint calculator to add them, and allow for skips, parking and VAT if your trades are registered.
Contingency
Keep 10–15% aside for surprises: blown plaster, a damaged subfloor, or a change of plan halfway through. Our guide to budgeting a renovation explains how to make the number survive the job.
Bathrooms and kitchens
What this calculator does not cover
This calculator covers decorating and flooring. A bathroom or kitchen renovation also involves plumbing, electrics, plastering, sanitaryware or units, and often tiling. Those vary so much between jobs that they need a quote from a fitter.
Parts you can still estimate
Use the tile calculator for wall and floor tiling, and the flooring calculator to compare LVT or vinyl for a waterproof floor. That gives you a solid number for the finishes before the fitter prices the rest.
DIY or hire in?
What doing it yourself saves
In the mid-range example, materials are £736 and labour £880. Doing the work yourself saves the £880 — 54% of the total. Set labour days to zero in the calculator to see your materials-only figure.
That saving is real, but budget for rollers, brushes, a mitre saw or knee pads, and for taking longer than a trade would.
Where a trade earns their fee
Straight walls in a bedroom are a reasonable DIY job. Stairwells, high ceilings, solid wood floors and anything involving electrics or plumbing are where professional work saves time, mistakes and sometimes safety risks.
Planning more than one room
Order of work
Do the messy jobs first. Plastering and electrics come before decorating, and decorating comes before new flooring, so paint is not dropped on a new floor. Ceilings are painted before walls, and walls before skirting boards.
Adding up the house
Three bedrooms at the mid-range figure come to £4,848. Hallways and stairs have more wall area than their floor size suggests, so measure them properly rather than treating them as a small room. Tradespeople often price a multi-room job for less per room than a single room.
Choosing a quality tier
The tier changes the price of the paint and the flooring, not the labour. Premium paint often covers better, which can save a coat, and better flooring lasts longer in busy rooms. For bedrooms that get light wear, mid-range is usually the sensible middle. Spend more where wear is heavy — hallways, stairs and kitchens.
Use these figures to set a budget and compare quotes line by line. They are estimates, not a quote.