Project cost estimator
List the materials for a home project with quantities and prices, add labour and delivery, and put a contingency on top for surprises. Add sales tax or VAT if your prices exclude it. The total, the split and the cost per unit are shown as you type.
Materials
Labour and extras
About the project cost estimator
List the materials for a home project with quantities and prices, add labour and delivery, and put a contingency on top for surprises. Add sales tax or VAT if your prices exclude it. The total, the split and the cost per unit are shown as you type.
Part of SmartCalcy’s home & construction tools. It runs in your browser with no account, uses your own currency and units (change them at the top of the page), and gives estimates for information only, so check official guidance before you rely on a result.
How to use the project cost estimator
What it calculates and when to use it
Builds a budget for a home or DIY project: materials with quantities and prices, labour, delivery and hire, a contingency for surprises and tax if your prices exclude it.
How to use it, step by step
- List each material with a quantity and a price.
- Add labour, delivery and hire.
- Choose a contingency, typically 10–15%.
- Add tax if your prices exclude it, and a size for a cost per square metre or foot.
What each input means
- Materials – Item, quantity and price each; up to 30 rows.
- Labour – From a written quote.
- Contingency – Starts at 10%.
- Tax to add – Leave blank if prices include it.
- Project size – Optional, for a cost per unit area.
How to read the results
- Estimated total – Everything including contingency and tax.
- How it adds up – Materials, labour, delivery, subtotal, contingency and tax, with each part’s share.
- Items – The cost of each line.
The formula
Subtotal = materials + labour + delivery. Contingency = subtotal × rate. Total = (subtotal + contingency) × (1 + tax rate).
A worked example
With the starting entries in pounds (paint 2 × 28, tools 18, filler 9, labour 240, 10% contingency) the subtotal is 323, the contingency 32.30 and the total 355.30.
Assumptions and limits
- Prices are in the currency shown at the top of the page and are not converted.
- The contingency is applied before tax.
Common mistakes
- Leaving out small items such as fillers, tape and fixings.
- Comparing quotes that cover different work.
- Setting the contingency to zero on an older building.
Frequently asked questions
How much contingency should I add?
10–15% is common for decorating; more for older buildings, extensions or anything structural.
Should I include tax?
Only if your prices exclude it. Trade prices often exclude VAT or sales tax.
Can I add more items?
Yes, up to 30 lines.
Related tools
How it adds up
- Materials
- £83.003 items
- Labour
- £240.00
- Subtotal
- £323.00
- Contingency
- £32.3010%
- Total
- £355.30
| Item | Qty | Each | Cost |
|---|---|---|---|
| Paint (5 L) | 2 | £28.00 | £56.00 |
| Brushes and rollers | 1 | £18.00 | £18.00 |
| Filler and sandpaper | 1 | £9.00 | £9.00 |