About SizeTheJob
SizeTheJob builds fast, accurate construction-materials calculators that answer one question before you spend money: how much do I need? Free, no sign-up, and every page shows the math.
How the calculators work
Every calculator runs on one shared, unit-tested math engine. For bulk materials it computes the volume of your area (length × width × depth, with shape options for circles, triangles, and L-shapes), converts to cubic yards (1 yd³ = 27 ft³), and applies the material’s density to estimate tons and bags. Decking and retaining-wall calculators use their own purpose-built math for board counts, linear feet, courses, and blocks. We show the formula and the constants on every page so you can check the result yourself.
Where our numbers come from
Accuracy is the whole point, so the densities and constants live in a single reviewed data file, each with a cited reference, and every output is checked against hand calculations and an independent reference tool. Bulk densities vary with moisture and compaction, so we show a realistic range alongside the working figure rather than pretending a single number is exact. Where a material is sold by the ton, by the cubic yard, or by the bag, we give you all three so you can match how your supplier quotes.
Who builds it
SizeTheJob is an independent tool built and maintained by Boringhaus, a small studio focused on simple, genuinely useful web tools. We are not a materials supplier and we don’t sell anything — the calculators are free, and we keep them that way.
Accuracy & disclaimer
Our results are careful estimates, not guarantees. Real-world quantities vary with moisture, compaction, waste, site conditions, and how a supplier measures — always confirm with your supplier before you order, and round up. For structural work, retaining walls over about 3–4 feet, or anything that needs a permit, consult a qualified professional. SizeTheJob is not liable for material shortfalls, overages, or costs based on these estimates.
Last reviewed May 2026.