Sand & Aggregate Calculator

The material bill for concrete always reduces to the same three questions — how much cement, how much sand, how much stone — and the answer lives entirely in the mix ratio. Once you know the wet volume that needs filling and the parts of the ratio, the split is pure arithmetic: every ratio has a fixed number of parts, and each material takes its share of the dry volume.

Sand & Aggregate Calculator works purely from that ratio. Give it a concrete volume in cubic metres, feet or yards — or a number of cement bags — and a mix from M5 to M25 or a custom cement-sand-aggregate ratio, and it returns the cement, sand and coarse aggregate in cubic metres, kilograms and tonnes, plus the water and the total weight of the batch.

Underneath is a guide to the ratios, the bulk densities that turn volume into weight, and the dry-volume factor that makes the numbers work on site. Everything runs in your browser; nothing is uploaded.

• Ratio-first by design: Everything is driven by the cement-sand-aggregate ratio, with presets M5 to M25 and a fully custom mix.
• Work from volume or bags: Start from concrete volume or from cement bags — the calculator converts both directions through the same ratio.
• Three volume units: Cubic metres, cubic feet and cubic yards for the wet concrete volume.
• Full material split: Cement in m³, kg and bags; sand and aggregate in m³, kg and tonnes with the parts clearly shown.
• Standard densities built in: 1440 kg/m³ cement, 1600 sand and 1560 aggregate, with the figures used shown in the report.
• Dry factor and waste: The 1.54 dry-volume factor and an adjustable waste allowance keep the order honest.
• Water estimate: Litres of water from the water-cement ratio for the chosen grade.
• Weight check: Total batch weight in tonnes, useful for wheelbarrow counts, truck payloads and cost checks.
• Reports & export: Copy or download the material bill as text, CSV or JSON.
• Learning guide: Ratio tables, density figures and ordering tips built into the tool.

1. Pick the input. Concrete volume for a job, or cement bags when you already know the stock you have.
2. Enter the quantity. Perfect volume in m³ / ft³ / yd³, or the number of bags and the bag size.
3. Choose the ratio. M15 (1:2:4) for general work, M20 or M25 for heavier members, or enter a custom ratio.
4. Set the waste allowance. 5 percent is the sensible default for spillage and uneven mixes.
5. Read the split. Cement, sand and coarse aggregate appear in volume, weight and bags.
6. Check the weight. The total tonnes figure helps you plan handling and transport.
7. Export the bill. Copy or download the report as text, CSV or JSON for your order.

Example 1 — 2.25 m³ at M15. A 5 × 3 × 0.15 m slab. With 1:2:4 and 5% waste the dry volume is 3.64 m³, giving 0.52 m³ cement (15 bags), 1.04 m³ sand and 2.08 m³ coarse aggregate — about 1.66 t of sand and 3.24 t of stone.

Example 2 — By bags. You have 20 bags of cement on site. Each is 0.0347 m³, so at M15 you have 0.69 m³ of cement, 1.39 m³ sand and 2.78 m³ aggregate — enough for roughly 2.9 m³ of finished concrete.

Example 3 — One cubic metre at M20. The ratio 1:1.5:3 has 5.5 parts.1 m³ wet = 1.62 m³ dry gives 0.29 m³ cement (9 bags), 0.44 m³ sand and 0.88 m³ stone.

Example 4 — Mixing by weight. A contractor mixes by buckets. Feeding 10 m³ of wet volume at M25 (1:1:2) gives 4 parts → 1.62 m³ cement, 1.62 m³ sand, 3.23 m³ stone, letting you calibrate bucket counts for every drum.

Example 5 — Checking ready-mix. A plant quote of 6 m³ ready-mix at M15 should consume about 38 bags of cement-equivalent, 2.77 m³ sand and 5.54 m³ aggregate in design quantities — a quick sanity check before you accept the order.

• Know the whole bill: Cement, sand and aggregate in one view, in volume and weight, from a single ratio.
• Convert both directions: Volume to materials, or bags to the concrete they will actually make.
• Fix your ratios: Presets for every standard grade plus a custom ratio for non-standard mixes.
• Order in tonnes: Aggregate is usually sold by weight — the tonne figures line up with supplier pricing.
• Verify the maths: The parts, dry factor and densities are all shown, so the estimate is transparent.
• Plan handling: Total batch weight in tonnes helps with wheelbarrows, dumpers and site logistics.
• Export the bill: Text, CSV and JSON summaries drop straight into orders and cost sheets.
• Free and private: No account, no watermark, nothing uploaded.