How much soil will your dig actually produce, and how many truck loads is that?
A 10 metre by 6 metre pad cut 300mm deep is 18 cubic metres in the ground. Dug clay bulks up around 28 percent, so that is roughly 23 loose cubic metres, about 34 tonnes, five loads in an 8 tonne tipper, and $2,200 to $3,800 to dig out and cart away in Casey in 2026. Length by width by depth, then add the bulking. That second step is the one most people miss.
What this estimator includes, and what it deliberately leaves out
- It sizes and prices the excavation and disposal: machine, operator, float, loading and cart away with dockets. That is the part that scales with volume.
- It excludes imported material. Crushed rock, sand and clean fill are priced separately by the tonne on our crushed rock and fill guide.
- It excludes concreting, paving, retaining, plumbing connections and landscaping, because we do not do those trades.
- It excludes council permits, the City of Casey asset protection permit and any crossover permit.
- Weight based truck loads assume clay at about 1.9 tonnes per in-ground cubic metre. Wet winter clay is heavier and takes more loads.
- It is a 2026 guide for the City of Casey. A firm price needs somebody standing on the block. For rate by rate detail see the pricing guide.
How to measure it properly with a tape and a phone
You do not need a surveyor to get within 10 percent, which is close enough to know whether you are having a conversation about $2,000 or $12,000.
- Measure the footprint at ground level. Not the roof line, not the eave, not the fence. Pull the tape along the actual line the machine will cut to, and add the working room the builder has asked for, usually 300mm to 600mm outside the slab edge.
- Get the depth with a string line, not a guess. Knock a peg in at the highest corner, run a builder’s line to the lowest corner and level it with a line level or the level app on your phone. Measure down from the string at each corner and average the four numbers. That average is your cut depth.
- Measure from the finished level, not the grass. The topsoil comes off first and it is almost always deeper than people think. If you can push a screwdriver in to the handle, that is still topsoil.
- Walk trenches with the tape and count the bends. A 25 metre run at 300mm wide and 600mm deep is 4.5 cubic metres. Every 90 degree bend adds a little dig time even though it adds no volume.
- Photograph every corner with the tape in the shot. Text them through with the numbers. Nine times out of ten we can price the job off the photos without a second visit.
- No tape? Pace it. An adult pace is roughly 750mm. Check yours against a known 10 metres first and you will be within half a metre over a house pad.
The allowances to add, every time
- Bulking. Soil expands when you dig it. Add 15 to 20 percent for sandy loam, 25 to 35 percent for Casey clay, and 45 to 60 percent for rock and broken concrete. This is what decides truck loads.
- Shrinkage on the way back in. Fill loses volume as it is compacted. Order 1.2 to 1.25 loose cubic metres for every compacted cubic metre you need in the ground.
- Rock by weight. Crushed rock runs about 2.2 to 2.4 tonnes per compacted cubic metre. Multiply your compacted volume by 2.25 to get tonnes, then add 10 percent for wastage and trimming.
- Batters and safe sides. Anything deeper than about 600mm needs the sides battered back, and a trench deeper than 1.5 metres is high risk construction work in Victoria that must be benched, battered or shored. That safety allowance is volume you have to pay to move. A 1 metre deep cut battered at roughly 1 to 1 adds a metre all the way round.
- Five percent on pipe and fabric, ten percent on rock. Running short by half a load costs more than the extra material.
- Do not order the last load until the pad is trimmed. Order to about 90 percent and top up. Surplus rock in your driveway is money you cannot get back.
Send us your measurements and we will do the sums
Text the corner photos and the numbers and we will come back with the volume, the loads and a fixed price, usually the same day.
The sizing mistake that costs the most in Casey
Underestimating the topsoil. Everybody assumes 150mm because that is what it looks like from standing height. On the old market garden ground through Cranbourne, Clyde and parts of Officer, there is often 300mm to 500mm of worked, organic topsoil with no bearing value, and every millimetre of it has to come off before anything structural goes down. On a 63 square metre pad that turns a 9.5 cubic metre strip into 19 to 31 cubic metres. At $280 to $480 a tipper load, that is three or four extra loads and $1,000 to $1,900 that was not in anybody’s budget.
Two more that catch people out. Forgetting the batter, which on a 1 metre deep cut can add more volume than the cut itself. And measuring the slab and not the working room, because the builder needs 300mm to 600mm outside the slab edge to set formwork and that strip is dug too. If you want the cheapest way to handle a big volume once you know the number, the budget earthworks guide has the staging options.
A worked example on a real Casey job
A double garage pad in Narre Warren South. Slab is 9 metres by 7 metres, so 63 square metres. The block falls 450mm across the 9 metre length, which is typical for that part of Casey. Here is the whole calculation:
- Topsoil strip: 150mm over 63 square metres = 9.5 cubic metres.
- Balanced cut: to sit the pad level, the high half needs an average 112mm off over 31.5 square metres = 3.5 cubic metres.
- Total dug: 13 cubic metres in the ground.
- Bulked: 13 x 1.28 = 16.6 loose cubic metres. At 1.9 tonnes a cubic metre in the ground that is about 25 tonnes, which is four loads in an 8 tonne tipper.
- Fill needed on the low half: 3.5 compacted cubic metres. Stripped topsoil cannot be used as structural fill, so that is imported: about 8 tonnes of Class 3.
- Pad sub-base: 150mm over 63 square metres = 9.5 compacted cubic metres, about 21 tonnes, order 23 with wastage.
- Total rock: 31 tonnes at $52 to $70 delivered = $1,610 to $2,170.
Put 13 into the estimator above with clay, carted off site and open access and it returns $1,700 to $3,000 for the dig and cart away. Add the rock at $1,610 to $2,170, and half to a full day to spread and compact in lifts at $440 to $980. The whole shed pad lands at roughly $3,750 to $6,150 in 2026, which is exactly what we would quote it at. Nothing in that number is a surprise, because every line of it came out of a tape measure.
When the answer is that you do not need to move any soil
If your block already sits within about 100mm of the level you need over the footprint, you are not looking at a cut and fill job, you are looking at a topsoil strip and a base. That is half a day, not three days. If you are levelling a lawn or filling a dip, buy four or five cubic metres of screened soil and a rake rather than putting a machine on it. And if the volume you have measured is under about 3 cubic metres, a skip bin and a shovel will beat any machine we can float in, because our minimum charge covers the float either way. We would rather tell you that on the phone.
For the jobs where the volume is real, the type of dig changes the rate as much as the volume does: a pool excavation is priced differently to a drainage trench, and both are different again to a bulk cut. Once you have your number, the day by day guide covers what happens next.
Sizing questions we get asked
How do I work out how much soil my dig will produce?
How many cubic metres fit in a tipper truck?
How much does dug clay weigh?
How much crushed rock do I need to fill a hole back in?
What is the sizing mistake that costs the most in Casey?
Do I need to allow extra volume for the sides of the hole?
Send your measurements, get the volume and a fixed price
Give us the dimensions or the photos and we will come back within one business day with the cubic metres, the truck loads and the number.
Rather we measured it for you?
Free 30 minute site visit across Berwick, Cranbourne, Narre Warren, Hampton Park and Endeavour Hills. Fixed written quote within 48 hours.