How much sand do I need for one bag of cement?

It depends on the mix. For a 25 kg bag of cement (about 19 litres): 1:3 takes about 57 litres of sand (≈ 91 kg), 1:4 about 76 litres (≈ 122 kg, roughly five 25 kg bags), 1:5 about 95 litres (≈ 152 kg) and 1:6 about 114 litres (≈ 182 kg).

How much sand and cement do I need per m²?

For a 5 cm floor screed at 1:4: about 80 kg of sand and 16 kg of cement per m². For a render base coat at 1:5: about 16 kg of sand and 2.6 kg of cement per m² for each centimetre of thickness. For an 11 cm brick wall at 1:4: about 21 kg of sand and 4.3 kg of cement per m².

How much cement do I need for 1 tonne of sand?

One tonne of dry sand is about 0.63 m³ (625 litres). At 1:4 that needs about 156 litres of cement, roughly 8 bags of 25 kg. At 1:3 it is about 11 bags, at 1:5 about 7 bags and at 1:6 about 5 to 6 bags.

How many m³ is 1 tonne of sand?

About 0.63 m³ of dry, loose sand. The other way round, 1 m³ of sand weighs about 1.6 tonnes. Damp sand weighs more for the same volume.

What is the best sand and cement mix for a patio?

Block paving is usually laid on a bed of sharp sand 3 to 5 cm thick, with no cement. Patio slabs laid on a full mortar bed typically use 1:4 to 1:5. At 4 cm and 1:4, that is about 64 kg of sand and 13 kg of cement per m². Follow the paving manufacturer's instructions for thickness.

How many buckets of sand go with one bag of cement?

With 10-litre buckets, a 25 kg bag of cement is about 2 buckets. A 1:4 mix then takes about 8 buckets of sand and a 1:5 mix about 9 to 10 buckets. Buckets are more reliable than shovels, which vary with the shovel and the person filling it.

How Much Sand and Cement Do I Need? Ratios & per m²

Chambino Areias supplies sand in Portugal only (Seixal, near Lisbon). Prices exclude VAT; delivery to site from 5 t across the Lisbon and Setúbal region; smaller orders are collected at the pit.

How the Calculation Works

A mix such as 1:4 is a ratio by volume: 1 part cement to 4 parts sand. To turn it into kilos and bags you only need three figures:

A 25 kg bag of cement takes up about 19 litres.
Dry, loose sand weighs about 1.6 kg per litre (1 m³ ≈ 1.6 tonnes).
One m³ of finished mortar uses about 1 m³ of loose sand: the cement and water fill the gaps between the grains, so the mix does not add up to the sum of its parts.

Sand (litres) = 19 × the sand number in the mix

Example at 1:4: 19 × 4 = 76 litres × 1.6 = about 122 kg of sand per bag of cement

Sand per Bag of Cement

Per 25 kg bag of cement, with dry sand:

Mix	Sand (litres)	Sand (kg)	25 kg sand bags	10 L buckets
1:3	≈ 57 L	≈ 91 kg	3 to 4	≈ 6
1:4	≈ 76 L	≈ 122 kg	≈ 5	≈ 8
1:5	≈ 95 L	≈ 152 kg	≈ 6	9 to 10
1:6	≈ 114 L	≈ 182 kg	≈ 7	≈ 11

Measure in buckets, not shovels. A shovelful changes with the shovel, with the person filling it and with how wet the sand is. A 10-litre builder's bucket filled level every time keeps the mix consistent from one batch to the next. One bag of cement is about two buckets.

Sand and Cement per m², by Job

Typical mixes used on site, the same ones our simulator uses. Figures are without the waste margin.

Job	Mix	Sand per m²	Cement per m²
Floor screed, 5 cm	1:4	≈ 80 kg	≈ 16 kg (⅔ bag)
Floor screed, 5 cm	1:3	≈ 80 kg	≈ 22 kg (0.9 bag)
Render base coat, per cm of thickness	1:5	≈ 16 kg	≈ 2.6 kg
Render finish coat, 0.5 cm (fine sand)	1:6	≈ 8 kg	≈ 1.1 kg
Brick wall, 11 cm brick, 1 cm joints	1:4	≈ 21 kg	≈ 4.3 kg
Block wall, 20 cm concrete block	1:4	≈ 39 kg	≈ 8 kg
Patio slabs on a mortar bed, 4 cm	1:4	≈ 64 kg	≈ 13 kg
Block paving on a sand bed, 4 cm	sand only	≈ 64 kg	none
Concrete slab, 10 cm (site-mixed)	≈ 1:2:3	≈ 77 kg	≈ 35 kg

Floor screed

Screed is usually 1:3 to 1:4 with coarse washed sand 0/4, never fine sand: fine grains need more water and give a weaker screed. Every centimetre of thickness adds about 16 kg of sand per m². For a full walkthrough see our guide on how to calculate the amount of sand.

Rendering

Traditional render goes on in layers. The base coat uses coarse washed sand 0/4 at about 1:5 (1:4 to 1:5 in practice), around 1 to 1.5 cm thick indoors and 2 cm outside. The finish coat, about 0.5 cm, uses fine washed sand 0/1 at 1:5 to 1:6 for a smoother surface. Walls that need more than 3 cm should be built up in several coats.

Brick and block walls

Bricklaying mortar is commonly 1:4 to 1:5. The figures in the table assume 1 cm joints; thicker joints or hollow blocks that swallow mortar push them up.

Patios and paving

Block paving is normally laid dry, on a 3 to 5 cm bed of sharp sand over a compacted sub-base, with fine sand brushed into the joints. Patio slabs are often laid on a full mortar bed instead, at 1:4 to 1:5. In both cases the bed thickness should follow the paving manufacturer's instructions.

Concrete

A site-mixed concrete at roughly 1:2:3 takes, per m³, about 350 kg of cement (14 bags), 0.48 m³ of sand (≈ 770 kg) and 0.71 m³ of gravel. That suits small non-structural jobs. Footings, columns and structural slabs should follow the engineer and are usually better done with ready-mix concrete.

How Much Cement for 1 Tonne (or 1 m³) of Sand

If you have already bought the sand, work backwards. One tonne of dry sand is about 625 litres.

Mix	Cement per tonne of sand	Cement per m³ of sand
1:3	≈ 11 bags (≈ 270 kg)	≈ 17 to 18 bags
1:4	≈ 8 bags (≈ 205 kg)	≈ 13 bags
1:5	≈ 7 bags (≈ 165 kg)	≈ 10 to 11 bags
1:6	≈ 5 to 6 bags (≈ 140 kg)	≈ 9 bags

Bags are 25 kg of cement.

Sand Measurements: Tonnes, m³, Litres and Bags

Dry, loose sand	Equals about
1 m³	1.6 tonnes (1,600 kg), or 64 bags of 25 kg
1 tonne	0.63 m³ (625 litres)
1 litre	1.6 kg
1 bag of 25 kg	16 litres
1 big bag (≈ 1 tonne)	0.6 m³, or 40 bags of 25 kg

What about "a load of sand"? It is not a fixed unit: it depends on the truck, from a few tonnes on a small tipper to well over 10 tonnes on a large one. Always order and compare prices in tonnes (or m³), not in loads.

Wet sand changes the numbers. Damp sand is heavier and bulks up, taking more volume for the same amount of dry material. If your sand is wet, mix a test batch and adjust the water rather than the sand.

Worked Examples

1. Screed for a 20 m² room, 5 cm, 1:4

Volume: 20 m² × 0.05 m = 1 m³
Sand: 1 m³ × 1.6 t/m³ = 1.6 t; with a 10 % margin ≈ 1.8 t
Cement: 1 m³ of sand at 1:4 ≈ 13 bags; with the margin ≈ 14 to 15 bags
2 big bags of coarse washed sand 0/4 (or about 72 bags of 25 kg) and 15 bags of cement

2. Rendering 40 m² of interior wall, 1.5 cm in total

Base coat, 1 cm at 1:5: 40 × 16 kg = 640 kg of sand 0/4 and 40 × 2.6 kg ≈ 104 kg of cement
Finish coat, 0.5 cm at 1:6: 40 × 8 kg = 320 kg of fine sand 0/1 and 40 × 1.1 kg ≈ 44 kg of cement
With a 10 % margin: ≈ 700 kg of sand 0/4, ≈ 350 kg of sand 0/1, ≈ 6 to 7 bags of cement
1 big bag of sand 0/4 and 14 bags of 25 kg of fine sand 0/1

3. Patio of 15 m² with slabs on a 4 cm mortar bed, 1:4

Sand: 15 × 64 kg = 960 kg; with a 10 % margin ≈ 1.06 t
Cement: 15 × 13 kg = 195 kg; with the margin ≈ 9 bags
About 1 big bag of sand (or 43 bags of 25 kg) and 9 bags of cement

Examples 2 and 3 are below our delivery minimum: in Portugal, orders that size are collected at the pit in Seixal.

Which Sand to Use

Coarse washed sand 0/4 (grains from 0 to 4 mm, close to what is sold as "sharp sand" in the UK): screed, render base coats, bricklaying mortar, paving beds and site-mixed concrete. See washed sand 0/4.
Fine washed sand 0/1 (grains up to 1 mm): render finish coats, detail work and paving joints. See fine washed sand 0/1.

Washed sand has had the clay and silt rinsed out, so mortars bond better and shrink less. For the difference in detail, see washed sand vs natural sand and types of sand for construction.

Common Mistakes

Mixing ratios by weight: mixes are by volume. 1:4 by weight gives much less cement than intended.
Counting shovels: use a bucket so every batch is the same.
Adding sand and cement volumes together: 1 m³ of sand plus cement does not make 1.2 m³ of mortar; it makes about 1 m³.
Forgetting the margin: add 10 to 15 % for waste and uneven surfaces.
Using fine sand for screed: keep fine sand for finishes; screed needs coarse sand.

Working in Portugal?

Send us your measurements and we will tell you how much sand you need and in which format: 25 kg bags, big bags of about 1 tonne, or bulk for washed sand 0/4. You can also try the simulator (in Portuguese).