Excavation Calculator
Estimate dig volume, swell-adjusted loose volume, truck loads and project cost for trench, footing, basement, pit & road excavation — with engineering drawings and a printable PDF report.
Material cost estimate (optional)
How to estimate excavation
Three simple steps to a complete dig-volume and haulage estimate.
Trench, footing, basement, pit, road or custom dig — choose the type so the right slope geometry and volume formula are applied.
Add length, width and depth, plus side slope, soil type and over-dig allowance. Metric and imperial units both work.
Bank volume in cubic yards and metres, swell-adjusted loose volume, truck loads, footprint and optional cost — clearly broken down.
Excavation Calculator — Free & Accurate
Our excavation calculator helps site engineers, estimators, contractors, and DIY builders work out how much soil a dig will produce and how many truck loads it takes to haul away. Pick a type — trench, footing, basement, pit, road, or custom — enter the dimensions and side slope, and get a complete volume and cost estimate in seconds.
Volume is computed from your dig geometry including the side-slope batter. For trenches and road cuts, only the two long faces are battered, so the volume uses the average-width method: V = L × D × (W + s·D). For pits, basements, footings and custom digs, all four faces slope, so the calculator uses the full frustum formula V = L·W·D + s·(L+W)·D² + (4⁄3)·s²·D³, where s is the slope ratio (horizontal run per unit of vertical rise). The result is the bank (in-situ) volume.
Because excavated soil expands, the calculator then applies your soil's swell/bulking factor to give the loose volume that must actually be hauled away — and divides that by your truck capacity to estimate loads. Results show bank volume (cu yd and cu m), swell-adjusted loose volume, truck loads, dig footprint, and over-dig allowance — plus an optional cost estimate covering excavation, disposal and equipment in your local currency. Everything runs in your browser — no signup, no data sent to any server.
Why use this calculator?
Built for the site, not the spec sheet — simple, fast, and accurate.
No spreadsheets, no formulas to memorise. Type your sizes, hit calculate, and you're done.
Applies side-slope batter geometry, deducts nothing you didn't dig, and handles soil swell and truck loads automatically.
Everything runs in your browser. Your dimensions never leave your device.
Mix metres, feet, inches, and centimetres on the same job — the math converts cleanly.
Tells you bank volume, loose volume and truck loads — exactly what your earthworks crew and haulage contractor need to quote.
Open it on your phone right at the workshop. Fully responsive, no app needed.
Related construction tools
Free, browser-based, and built the same way as the excavation calculator.
Frequently asked questions
Bank volume (also called in-situ or solid volume) is the soil as it sits undisturbed in the ground — this is what you physically dig out and what excavation is usually priced against. Loose volume is the same soil after digging, when it has expanded and become aerated; it is always larger and is what determines how many truck loads you need to haul away. Compacted volume is smaller again, relevant when the soil is re-used as fill. This calculator reports bank volume as the headline and applies your soil's swell factor to give the loose volume for haulage.
Excavations in anything but firm rock are battered (sloped) back for stability, so the dig is wider at the top than the bottom. Side slope is given as a ratio of horizontal run to vertical rise — a 1:1 slope moves the top edge out by one unit for every unit of depth. For trenches and roads only the two long sides batter, so volume = L × D × (W + s·D). For pits, basements and footings all four faces batter, which adds material in the corners too: V = L·W·D + s·(L+W)·D² + (4⁄3)·s²·D³. Steeper (smaller) slope ratios mean less excavation; flatter ratios mean more.
Swell (bulking) is how much soil expands once excavated. Typical figures: sand and gravel ~10–15%, common earth and loam ~25%, clay ~30–40%, and blasted rock ~50–65%. Wet or dense clays sit at the high end. The calculator's soil-type presets fill these in for you, or you can choose "Custom" and enter your own percentage from a soil report. The swell factor only affects the loose (haulage) volume and truck-load count — it does not change the bank volume you dig.
Truck loads are based on the swell-adjusted loose volume — the soil that actually leaves the site — divided by your truck capacity, then rounded up to the next whole load. A typical tandem dump truck carries around 10–14 cubic yards; smaller tippers carry 6–10. Set your truck capacity in cubic yards, cubic metres or cubic feet to match the vehicles you'll use. Because soil swells, the load count is always higher than you'd get from the bank volume alone.
Yes. Every dimension has its own unit picker, so you can enter the length in feet, the width in metres and the depth in inches on the same calculation. The math converts everything internally and reports volume in both cubic yards and cubic metres so it matches whatever your supplier or haulage contractor quotes in.