Use this calculator to total the materials for a project once you know the quantities. Our other calculators give you the counts; enter each quantity with its price here, add sales tax and delivery, and keep a contingency for surprises.
How the cost calculator works
- Subtotal = the sum of quantity × unit price for each line.
- Sales tax = subtotal × your local tax rate.
- Contingency = (subtotal + tax + delivery) × contingency %. The default is 10%.
- Total = subtotal + tax + delivery + contingency.
Worked example
A bathroom floor needs 12 boxes of tile at $45, 3 bags of thin-set at $28 and 2 bags of grout at $22. The subtotal is $540 + $84 + $44 = $668. With 7% sales tax ($46.76), free delivery and a 10% contingency ($71.48), the total is $786.24.
How much contingency to add
| Project | Typical contingency |
|---|---|
| Simple, well-measured job (paint, mulch) | 5–10% |
| Flooring, tile, decking | 10–15% |
| Older house or hidden conditions | 15–20% |
| Work behind walls, under floors or on the roof | 20% or more |
Step by step: budgeting a project
Tips for an accurate budget
- Price the same brand and grade you will actually buy. Store-brand and premium prices can differ a lot.
- Fasteners, adhesives, tape and blades add up. Add a line for small items.
- Ask about delivery minimums and returns before you order.
- This calculator covers materials only. Tool rental, permits and labor are not included unless you add them as lines.
