Built for the person ordering the material
ProMaterialCalc is a set of free estimating tools for concrete, mulch, topsoil, gravel, and aggregate. It exists because most material orders are placed from a phone at the job site, and a short-order or an over-order costs real money either way.
Why we built it
Contractors and DIYers both end up doing the same arithmetic on a phone: convert dimensions to a volume, decide how much waste to allow, and work out how many bags or truckloads that really means. Doing it by hand is where the mistakes creep in, and a poured slab does not wait for a second delivery.
So the calculators do the conversion chain for you, in the same order a quantity takeoff would, and show each figure at once: base volume, waste-adjusted volume, yard, ton, and bag counts. Everything updates as you type, so you can try a deeper pour or a bigger bed and watch what it does to the order.
What you can count on
- No account and no sign-up. Open the page and get a number.
- Your dimensions stay in your browser and are never stored on our servers.
- Bag yields and densities come from published supplier data, not guesswork.
- The waste factor is yours to set, not hidden inside our maths.
Three estimators, one method
Each tool is tuned to how its material is actually sold, but they share the same calculation steps underneath.
Concrete & Slab Estimator
Rectangular slabs and round piers, priced out in cubic yards with 60 lb and 80 lb bag counts.
Open the estimatorMulch & Topsoil Estimator
Garden beds and tree rings, converted to cubic feet and cubic yards with bag sizing.
Open the estimatorGravel & Aggregate Estimator
Driveways and base layers, measured in tons using the bulk density of the material you pick.
Open the estimatorHow the numbers are worked out
Four steps, applied to every material on the site.
- Step 1
Measure the shape
Every estimator starts from the dimensions you already have: length, width, diameter, and depth.
- Step 2
Convert to cubic feet
Volume is worked out in cubic feet first. That keeps the maths the same whether you are pouring a slab or filling a bed.
- Step 3
Convert to yards, tons or bags
Cubic feet convert to cubic yards for ready-mix and bulk materials, to short tons using the material's density, and to bag counts using published bag yields.
- Step 4
Add your waste buffer
A waste factor of 5 to 10 percent covers spillage, uneven sub-grade and the extra you always end up needing.
What we won't pretend to do
These are estimating tools, not engineering advice. Sub-grade compaction, frost depth, reinforcement, mix design, and local code all change the real answer, and none of them can be read off a web form. For structural work and anything requiring a permit, have the plans reviewed by a licensed engineer or your building department. Our estimation disclaimer spells out those limits. The published data behind every figure, and how each conversion is applied, is set out in the method and sources section.
Questions, corrections, or a material you'd like added?
Tell us what you were estimating and what number looked wrong. Supplier data changes, and we would rather fix a figure than leave it standing.