About us and where the numbers come from

Paving Planner is written by Michal Antal. It started for a friend who lays paving for a living and was working out areas and prices in the evening after work, on paper and on a phone calculator. Getting an area with cut-outs measured, the packs counted and a quote out of it took longer than the survey itself.

Everything the app works out sits in one layer of code with no dependency on the database or the interface: area from the outline, the volume of the build-up, tonnes of aggregate, the number of blocks including waste from cutting, lengths of kerb, and the quote maths with VAT. The same layer drives the free block paving calculator and the paid part of the app, so the two cannot drift apart.

The money and geometry calculations have automatic tests. That is a condition, not a habit: an error in VAT rounding or in an area with a hole in it is hard to spot and harder still to explain to a customer. Figures such as aggregate usage per m² or normal cutting waste were checked against real jobs rather than taken from the first search result.

The prices on the English pages are UK market figures, gathered from published price lists and contractor estimates. They are not euro prices run through an exchange rate, and they are not a quote — the real number is the one a contractor gives after seeing the site.

It does not replace a designer or a structural engineer. The calculation is a basis for a quote and a materials order, not construction documentation. It runs in a desktop browser, because drawing areas with a finger on a phone is misery and we would rather not promise something you would open on site and be annoyed by.

The text on this site sticks to what can be backed up. If you find a figure that does not match your experience, write in. We would sooner correct it than have it wreck somebody's costing.

Write to m.antal.work@gmail.com. Questions about the calculations and bug reports both get an answer.