Start with materials, not the whole project
Material costs are the most predictable part of a project and the easiest to estimate accurately — use the relevant calculator for each material (concrete, flooring, paint, drywall, and so on) to build a materials subtotal before pricing labour.
Pricing materials first also gives you a number to compare contractor quotes against: if a quote's material line is dramatically higher than your own estimate, it's worth asking why.
Set a contingency — and don't touch it early
A 10–20% contingency on top of your full estimated budget is standard advice for a reason: older homes especially tend to reveal problems (wiring, water damage, structural issues) once walls or flooring come up.
Treat the contingency as unavailable for scope upgrades. If you want a nicer fixture or a bigger tile partway through, that comes from a separate 'wants' budget — not the buffer that's protecting you from the unknown.
Sequence spending around irreversible decisions
Lock in structural and behind-the-wall decisions (plumbing, electrical, layout changes) before spending on finishes — changing a layout after tile or flooring is installed is far more expensive than getting it right on paper first.
Roll the numbers into one view
Once you have materials, labour, and delivery figures, put them in the Project Cost Estimator. Keep waste on the materials line and leave markup at 0% unless you are quoting as a trade.
The estimator shows a range on purpose. A single confident total is usually false precision. Use the range as a planning band, then confirm with local quotes before you order or hire.
Use a calculator for this
Project Cost Estimator
Roll materials, labor, delivery, waste, and optional markup into a planning total.
CalculatePaintingPaint Calculator
Estimate how much paint a room needs, based on wall area and coats.
CalculateFlooringFlooring Calculator
Work out how many boxes of flooring to buy for a room, with waste included.
CalculateHome ImprovementDrywall Calculator
Work out how many plasterboard or drywall sheets a room needs, including the ceiling.
CalculateFrequently asked questions
What percentage of a home's value should a renovation budget be?
There's no universal rule — it depends on your goals (living in the home long-term versus resale) and local market. It matters more that the budget matches your actual financial comfort than a rule of thumb.
Should I get financing before or after getting quotes?
Get a rough budget and at least preliminary quotes first, so you're financing an amount grounded in real numbers rather than guessing and either over-borrowing or coming up short mid-project.