Hardcore base-layer tool

Hardcore Calculator

Estimate hardcore volume, tonnes, and bulk-bag buying quantities for driveways, patio bases, shed bases, and general fill work.

Volume + tonnes + unitsWaste-aware resultBuying checks
Planning summary

Quick answer

Enter the footprint and compacted depth, add waste, then convert volume into tonnes, tons, bags, bulk bags, or loose delivery.

Planning summary

Watch most

The common misses are using an average depth on an uneven formation, forgetting compaction, and assuming a bulk bag or tonne quote matches the installed layer without checking density.

Planning summary

Best next move

Pressure-test the compacted design depth first, because a small change in depth usually moves the hardcore order more than people expect.

Quick buying answer

Enter the footprint and compacted depth, add waste, then convert volume into tonnes, tons, bags, bulk bags, or loose delivery.

Example: a 5m by 3m base at 100mm depth gives 1.5m3 before waste. Add 10 percent and the planning quantity becomes 1.65m3. At roughly 1.7 tonnes per m3, that is about 2.8 tonnes, which is close to four 0.85-tonne bulk bags.

Best for

Fast answer for a visible calculator search

Also searched as
hardcore calculatorhard core calculatorcrushed stone base calculator
Search upgrade focus

CTR and ranking lift: near page one with strong impressions.

Start with

Starter defaults assume a small patio, path, or shed-base build with around 100mm of compacted hardcore. If your supplier prices by tonne, change the bulk bag size to 1.

Last checked

June 4, 2026

We checked the page logic, support notes, and related links on this page.

How to use it

Planning before buying

Use this calculator for a planning check, then confirm the final order or quote against live product data and site conditions.

Plan the whole job, not just this number

Start with the planner when this estimate is only one layer of the job and the order needs several connected checks.

Project workflow6 calculators

Driveway Base Planner

Driveway base costs rise or fall on depth, compaction, membrane, delivery access, and the difference between fill and finished surface material. Plan those layers before comparing quotes.

Plan this job

Quote-ready brief

Use these actions to turn the live calculator result into a cleaner request for builders, suppliers, or merchants.

Run the calculator, then use these actions to prepare the estimate for a real quote request.

Need help deciding what to ask for? Read the quote checklist or contact the team at hello@buildcostlab.com.

Practical checks before you buy

These notes are where BuildCostLab goes beyond a generic calculator result by surfacing the assumptions, buying traps, and next decisions that usually move the real order.

Global terminology and buying units

Use this page across English-speaking markets by matching the local material name, unit, and buying format.

Also known as
crushed stone calculatorcrushed concrete calculatorrecycled aggregate calculatorbase rock calculator
Search intent
hardcore calculatorhard core calculatorcrushed stone base calculator
Quick answer

Enter the footprint and compacted depth, add waste, then convert volume into tonnes, tons, bags, bulk bags, or loose delivery.

Regional buying note

Hardcore is common UK wording. Other markets may use crushed stone, crushed concrete, recycled aggregate, road base, or base rock.

Unit examples

Use metres, feet, cubic metres, cubic feet, cubic yards, tonnes, short tons, bulk bags, or loose loads depending on how the supplier sells it.

What this estimate includes

The measured volume, waste-adjusted buying quantity, density or unit-size conversion, and a rough material spend when a price is entered.

What it may not include

Unexpected excavation differences, compaction behaviour, haulage constraints, and local delivery charges unless you add them separately.

Key assumptions

Hardcore estimates work best when the base footprint, compacted depth, and the likely loose-delivered buying route are all clear before ordering.

Worked example

Example: a 5m by 3m base at 100mm depth gives 1.5m3 before waste. Add 10 percent and the planning quantity becomes 1.65m3. At roughly 1.7 tonnes per m3, that is about 2.8 tonnes, which is close to four 0.85-tonne bulk bags.

How this estimate is worked out

We multiply length by width by depth, add the waste allowance, then convert the adjusted volume into tonnes or whole buying units using the stated density and delivery format.

What assumptions sit underneath it

Hardcore estimates work best when the base footprint, compacted depth, and the likely loose-delivered buying route are all clear before ordering.

How rounding is handled

Because bulk materials are bought by bag, bulk bag, tonne, or loose load, the final answer rounds to a real buying quantity rather than stopping at the theoretical trench or base volume.

What changes the result most

Compacted depth, density, level corrections, and whether the site suits bags, bulk bags, or loose tonnes usually move the hardcore order fastest.

Where people under-order

The neat footprint often misses soft spots, uneven formation, and the extra material needed when the site does not hold a perfect constant depth.

Practical buying checks

Compare bulk bags against loose tonnes, check if compaction changes the delivered quantity, and confirm whether membrane or top layers still need separate material checks.

Scope checklist

Use these prompts when you want to turn the estimate into a clearer builder, installer, or merchant request.

  • State the measured area, target depth, and whether the depth is compacted or loose-delivered.
  • Ask how the material will be supplied: bags, bulk bags, loose load, or ready-mix route where relevant.
  • Flag any access, storage, delivery, or waste-removal limits before the first quote is treated as final.

Plan the full job around this calculator

This calculator is one part of a larger buying list. Open the planner to check the related materials, accessories, guides, and quote notes.

Project workflow6 calculators

Driveway Base Planner

Driveway base costs rise or fall on depth, compaction, membrane, delivery access, and the difference between fill and finished surface material. Plan those layers before comparing quotes.

Plan this job

Explore this project hub

Open the full Aggregate and Base Estimating project hub to move from quick estimate to deeper guidance.

Related calculators for the same base-build job

Use these linked tools when the estimate also depends on sub-base depth, membrane separation, or adjacent drainage build-up rather than hardcore alone.

Sub-Base Calculator

Estimate sub-base volume, tonnes, and delivered quantity for paving, patios, paths, and driveway foundations before you order.

MOT Type 1 Calculator

Estimate MOT Type 1 volume, tonnage, bulk-bag buying quantities, and rough delivery needs for driveways, paths, and compacted sub-base layers.

Geotextile Membrane Calculator

Estimate geotextile membrane rolls, overlaps, and covered area for driveways, french drains, trenches, and separating aggregate layers.

Pipe Bedding Calculator

Estimate pipe bedding volume, tonnes, and bulk-bag buying quantities for drainage trenches before you order sand or gravel.

Keep planning the same job

These are the strongest next calculators when this estimate is only one part of the buying or quote-prep workflow.

Next stepAggregates

Sub-Base Calculator

Estimate sub-base volume, tonnes, and delivered quantity for paving, patios, paths, and driveway foundations before you order.

Next stepAggregates

MOT Type 1 Calculator

Estimate MOT Type 1 volume, tonnage, bulk-bag buying quantities, and rough delivery needs for driveways, paths, and compacted sub-base layers.

Next stepDrainage

Geotextile Membrane Calculator

Estimate geotextile membrane rolls, overlaps, and covered area for driveways, french drains, trenches, and separating aggregate layers.

Next stepDrainage

Pipe Bedding Calculator

Estimate pipe bedding volume, tonnes, and bulk-bag buying quantities for drainage trenches before you order sand or gravel.

Practical answers

Short answers for the buying questions that usually come up after the first calculation.

How do I use the Hardcore Calculator?

Enter the base dimensions, the installed hardcore depth, and a realistic waste allowance, then compare the result as cubic metres, tonnes, and buying units before you order.

What changes the Hardcore Calculator estimate most?

The biggest drivers are compacted depth, density, and whether the supplier is pricing by bag, bulk bag, or loose tonne rather than by a neat installed layer.

Should I round the result up?

Usually yes. Uneven formation, compaction, and delivery minimums often justify a modest overage rather than landing exactly on the theoretical volume.

Use this estimate in a quote request

Copy the estimate, add your own notes, and send the same scope to each builder or supplier so the quotes are easier to compare.

  • Confirm what the quote should include: materials only, labour only, or both.
  • State access, finish level, timing, and any unknowns clearly.
  • Ask each supplier or installer to price the same scope and exclusions.

You can also open the wider Aggregate and Base Estimating project hub if the quote depends on more than one material.