Mill & MerchantLearn · Plan · Build

Project tools

Project Cost Estimator

Add up the cost of your timber and materials, with an allowance for waste and the option to include VAT.

Related guidesSpecies data
Add your materials, get a running total. Type each item like a shopping list — the total, VAT and waste allowance update as you go.

Quick start

  1. Name each line for what you're buying — for example “CLS studs 47×100” or “OSB3 sheets”.
  2. Enter the quantity. Use whatever unit suits the line (pieces, sheets, packs) — just be consistent within that line.
  3. Enter the price for one unit, before VAT, in pounds.
  4. Use the waste % buttons to add a cutting allowance to every line, and the + Add a line button to build your list.

What each thing means

Material
A label so you recognise the line — it doesn't affect the maths. Type anything that helps you.
Quantity
How many units you're buying. The price is multiplied by this number.
£ each
The cost of one unit, before VAT. If a merchant quotes per metre, work out the price per piece first.
Waste allowance
Adds a percentage on top of every line to cover offcuts and mistakes — you always lose a little when cutting. 10% is a sensible default; 0% turns it off.
Include VAT
Switches the grand total between with and without 20% VAT. Always enter your prices before VAT and let this toggle add it.

Edit any line, or add and remove lines below. Nothing is saved — take a screenshot if you want to keep a copy.

Waste allowance
VAT

£211.75

£191.40

£99.00

Total (before VAT)

£502.15

3 lines · 10% waste allowance

Get better results

  • Don't forget the small stuff — screws, nails, glue and fixings add up fast, even on a simple build.
  • Buying by the pack, pallet or bundle is often cheaper than odd numbers of pieces — round up where it helps.
  • To keep or share a quote, take a screenshot. Nothing is saved, so your figures stay private.
  • Comparing merchants? Make sure every quote is on the same basis (all with VAT, or all without) before you judge.

Reading the numbers

Each line shows quantity × price, plus your waste allowance. The big total adds every line together, then adds VAT if you've switched it on. Figures are rounded to the nearest penny for display.

Not a substitute for structural sign-off

This is a quick materials estimate, not a full quote. It doesn't include delivery, tool hire, scaffolding, waste disposal or trade discounts. For anything you're committing money to get a written quote — and for structural work, professional sign-off.