Calculate My Reno gives you free material estimates to plan a job with. They are built to be honest and to show their working, but they are still estimates - so here is exactly what you can and cannot rely on before you spend money at the trade counter.
Every result is an estimate. The calculators use standard formulas and sensible wastage allowances, but real jobs vary - off-square rooms, odd cuts, breakages and supplier pack sizes all shift the number. Always check the quantity against your own measurements before you buy.
These tools are a starting point for planning, not a substitute for a builder, tradesperson or structural engineer. For anything load-bearing, regulated, or safety-critical, get a qualified professional to sign off the figures.
We round up to whole packs and add wastage, but we cannot see your room. Confirm coverage rates, units and pack sizes with your supplier - the bag, tin or box in front of you is the final word, not us.
Use the calculators at your own risk. We are not responsible for material shortfalls, surplus, wasted spend or any other loss that follows from relying on a result. If a number looks wrong, trust your tape measure. This sits alongside our terms of service.
In short
Treat every result as a well-informed second opinion. Measure twice, check the pack sizes with your supplier, and the calculators will save you a wasted trip - not replace your own judgement.
Last updated 2026
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