Sharp Sand Calculator
Find how many tonnes, tonne bags and 25 kg bags of sharp, building or plastering sand you need in Ireland.
Measure your project
Your answer
That is 0.48 m³.
If you buy bags
If you buy tonne bags
We found no Irish supplier that gives a weight for sand. We use 1.51 tonnes per m³, a UK figure from Wickes.
What it costs
Sharp or paving sand: €69.99 a tonne bag, the middle of 7 prices from 6 Irish sellers (Oct 2026). Prices include 23% VAT where the seller says so. Treat them as a rough guide.
Quick answers
- A 4 × 3 m patio bed, 40 mm deep
- About 0.72 tonnes of sharp sand. That is 1 tonne bag, or 29 bags of 25 kg.
- Weight of 1 m³
- About 1.51 tonnes. We found no Irish supplier that gives a figure, so this one is from Wickes in the UK.
- Sand for 100 blocks
- About 170–190 kg for solid 100 mm blocks, or 240–340 kg for hollow 215 mm blocks. We worked this out from Kilsaran's figures.
- 25 kg bags
- 40 bags make a tonne. A 25 kg bag of building sand costs about €5.25, the middle of 6 Irish sellers. That is with VAT where the seller says so.
- Bed under paving
- One Cork supplier, Power Aggregates, gives a sand bed of 25–40 mm under a patio in its guide.
How to work it out
- Measure the length and width in metres. Multiply them for the area in m².
- Pick the depth of sand in mm. Divide it by 1,000 to get metres.
- Area × depth = the volume of sand in cubic metres (m³).
- Multiply by 1.51 to get tonnes. We use this weight for every type of sand.
- Round the tonnes up to whole tonne bags. Tonnes × 40 = 25 kg bags.
4 × 3 × 0.04 = 0.48 m³
0.48 × 1.51 = 0.72 tonnes
0.72 tonnes → round up → 1 tonne bag
Sharp sand for common sizes, 40 mm deep
Each row is one area with a 40 mm bed of sand. Choose the one closest to your patio or path.
| Size | Tonnes | Tonne bags | 25 kg bags |
|---|---|---|---|
| 2 × 2 m | 0.24 | 1 | 10 |
| 3 × 3 m | 0.54 | 1 | 22 |
| 4 × 3 m | 0.72 | 1 | 29 |
| 5 × 4 m | 1.21 | 2 | 49 |
| 6 × 5 m | 1.81 | 2 | 73 |
| 10 × 5 m | 3.02 | 4 | 121 |
Flat ground, nothing extra. Bag counts are rounded up.
Sand coverage per tonne bag
This is the area one bag covers at each depth. Each tonne of sand is about 0.66 m³.
| Depth | Tonne bag (1,000 kg) | 25 kg bag |
|---|---|---|
| 25 mm | 26.5 m² | 0.66 m² |
| 40 mm | 16.6 m² | 0.41 m² |
| 50 mm | 13.2 m² | 0.33 m² |
| 75 mm | 8.8 m² | 0.22 m² |
| 100 mm | 6.6 m² | 0.17 m² |
Check the bag label. Irish quarries and most merchants say a tonne bag holds about 1,000 kg. Power Aggregates says a standard bulk bag holds 800–850 kg.
How much sand to lay blocks
Kilsaran's mortar leaflet says 1 m³ of mortar lays about 800 solid 100 mm blocks, laid on edge. The same mortar lays about 650 hollow 215 mm blocks.
Kilsaran's online calculator uses more mortar for hollow blocks and a little less for solid ones. So we show both figures as a range.
We turned the mortar into sand at about 1.54 tonnes of sand per m³ of mortar. This is a UK figure from the MPA, the top of its range.
| Blocks | Solid 100 mm | 25 kg bags | Hollow 215 mm | 25 kg bags |
|---|---|---|---|---|
| 100 | 170–190 kg | 8 | 240–340 kg | 14 |
| 250 | 430–480 kg | 20 | 590–850 kg | 35 |
| 500 | 850–960 kg | 39 | 1,190–1,710 kg | 69 |
| 1,000 | 1,710–1,930 kg | 77 | 2,370–3,420 kg | 137 |
Worked out, not a maker's figure. Bags are for the higher figure. Sand only: you also need cement.
So one tonne bag of building sand lays roughly 500–600 solid blocks, or 300–400 hollow ones.
Buying dry mortar in bags instead? Kilsaran's calculator uses 154 kg per 100 solid blocks. That is 7 bags of 25 kg.
Different types of sand: sharp, building and plastering
- Sharp sand: coarse sand that lets water drain. Irish sellers also call it paving sand or bedding grit. Murdock sells paving sand as a base for flags and pavers.
- Building sand: soft sand for mortar. Roadstone's mortar sand is a fine sand for laying bricks, blocks and paving.
- Plastering sand: fine washed sand for plaster and render, inside and out (Murdock).
- Jointing sand: dry sand you brush into the gaps between pavers (Roadstone).
Making concrete with cement, sand and gravel? Our concrete calculator covers mixes and bags.
Tonne bag prices
- Sharp or paving sand: €69.99, the middle of 7 prices from 6 sellers (€65–€101.50). Of the sellers we checked, only Irish Building Supply calls it "sharp sand".
- Building sand: €73.22, the middle of 10 sellers (€64–€79.99).
- Plastering sand: €72, the middle of 6 sellers (€66–€79.95).
- 25 kg bags of building sand: €5.25, the middle of 6 sellers (€4.46–€6.01).
Prices are from Oct 2026, with VAT where the seller says so. Revenue charges 23% VAT on sand. Not every seller says if VAT is in the price.
Sand for a patio or paving
- Lay a packed-down base of Clause 804. Roadstone sells it for patios and paving. Our gravel calculator works it out.
- Spread a bed of sharp sand, 25–40 mm deep. That is the depth in Power Aggregates' patio guide.
- Lay the flags or pavers on the sand.
- Brush jointing sand into the gaps. A 25 kg bag does 7–10 m², says Roadstone.
For a drive, check your local building rules or ask a builder or engineer.
Questions people ask
How much sharp sand do I need?
Multiply length × width × depth, all in metres, to get m³. Then m³ × 1.51 = tonnes. A 4 × 3 m patio bed at 40 mm takes about 0.72 tonnes.
How much sharp sand per m²?
About 38 kg for each m² at 25 mm deep, and 60 kg at 40 mm. So a tonne bag covers about 16.6 m² at 40 mm.
How much sand is in one cubic metre?
About 1.51 tonnes. That is a UK figure from Wickes, as we found no Irish one. So 1 tonne of sand is about 0.66 m³.
How much sand to lay 100 blocks?
About 170–190 kg for 100 solid 100 mm blocks, and 240–340 kg for 100 hollow 215 mm blocks. We worked this out. Kilsaran's leaflet and its online calculator give different mortar figures, so we show both.
How many shovels are in a 25 kg bag or a tonne of sand?
It depends on your shovel. One UK builders' merchant, Gilmore, says 10–12 shovels a bag. A bigger shovel needs fewer. At Gilmore's rate, a tonne (40 bags) is about 400–480 shovels.
How many wheelbarrows in a tonne of sand?
About 15–16 half loads, or 7–8 full ones. We worked this out for a barrow of 85–90 litres filled to the brim. A full load weighs 128–136 kg, which is heavy.
How much jointing sand do I need?
Roadstone says a 25 kg bag of its jointing sand covers 7–10 m² of paving. You brush it into the joints.
How much is a tonne bag of sand in Ireland?
About €69.99 for sharp or paving sand and €73.22 for building sand, in October 2026. Those are the middle of 7 prices from 6 sellers, and of 10 sellers. Prices include 23% VAT where the seller says so.
Where our numbers come from
- Sand weight: Wickes sharp sand bulk bag (800 kg covers 10.6 m² at 50 mm)
- Gravel and sand bed depths: Power Aggregates guides
- Gravel cover per tonne: Power Aggregates, Cork (12 m² at 50 mm)
- Mortar per block: Kilsaran K-Spread mortar flyer (Ireland)
- Blocks per m² and mortar per block: Kilsaran calculator
- Mortar and render mixes, cement and mortar per tonne of sand: MPA sheet 04
- Mixes, shovels per bag, cement per bulk bag: Gilmore Building Supplies guide
- Wheelbarrow sizes: B&Q Ireland (Walsall 85, 90 and 120 litres)
- Mortar (building) sand: Roadstone, 2 mm, for bricks, blocks, paving
- Sand types and prices: Murdock Builders Merchants (25 kg €6.01)
- Jointing sand: Roadstone (7–10 m² per 25 kg bag)
- Clause 804: Roadstone page (now called UGM, 0–31.5 mm)
- Sand and topsoil bulk bags: Irish Building Supply, Dublin/Wicklow
- Kilsaran bagged and bulk aggregates: sands, 20 mm stone, 804
- Tonne bag prices: the middle price from Irish sellers (Oct 2026)
- 25 kg sand bag price: the middle of 6 Irish sellers (Oct 2026)
- Tonne bags: CoreBuild, Dublin (gravel, hardcore, sand €67.65 inc VAT)
- Batch gravel tonne bag: Kenny Fuels, Wexford (€65 inc VAT, 1,000 kg)
- VAT on sand and gravel in Ireland: standard rate (Revenue)
- Irish VAT rates: Revenue (23%, 13.5%, 9%)
Made by BuildersCount. Last checked 4 Oct 2026.
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