How to Mix Concrete by Hand: Ratios, Water, and Technique
For small pours — a fence post, a garden step, a small slab — mixing concrete by hand is straightforward and doesn't require a drum mixer. The key variables are the proportions, the amount of water, and mixing until there are no dry pockets.
Cement, concrete or mortar?
These words get used interchangeably, but they are different materials:
So if you're "mixing cement by hand" for a slab or post, what you actually want is concrete — this guide. For brickwork, see our mortar mix ratio guide.
Safety first
Bagged concrete carries a DANGER label. Quikrete's safety data sheet warns that it "causes severe skin burns and serious eye damage", that cement burns "may not cause immediate pain or discomfort", and that the dust contains crystalline silica, which can cause silicosis and cancer through prolonged or repeated inhalation. Before you open a bag:
- Wear impervious gloves such as nitrile, eye protection, protective clothing and rubber boots
- Don't breathe the dust. The SDS calls for a NIOSH-approved respirator such as an N95 in poorly ventilated areas, for extended or frequent use, or where exposure limits may be exceeded
- On skin: remove contaminated clothing and wash the skin with cool water and pH-neutral soap. See a doctor if you suspect a burn or a rash develops
- In eyes: rinse cautiously with water for several minutes, remove contact lenses if easy to do, and keep rinsing. Get medical help if symptoms are significant or persist
Mix ratios
Concrete is made from cement, sand (fine aggregate), and coarse aggregate (gravel or crushed stone). For small jobs where nobody is designing a mix, the American Concrete Institute's proportioning guide (ACI PRC-211.1-22, Table A.7.1) lists starting mixtures by weight. These are its "Mixture B" figures for concrete without air entrainment, per cubic foot of finished concrete:
ACI's procedure: start with Mixture B, adding just enough water for a workable consistency. If the concrete looks short of sand, switch to its Mixture A (a little more sand); if it looks oversanded, switch to Mixture C (a little less). The figures assume surface-dry sand — ACI says to add 2 lb of sand per cubic foot if it is damp and 4 lb if it is very wet. ACI also says air-entrained concrete should be used in all structures exposed to freezing and thawing; that needs an air-entraining cement or admixture, and slightly less sand (43 lb instead of 47 lb for 3/4-inch gravel).
For example, a 2 ft³ batch with 3/4-inch gravel is 46 lb of cement, 94 lb of sand and 128 lb of gravel.
The 1:2:3 rule.On site, the most widely used shortcut is 1 part cement, 2 parts sand and 3 parts gravel by volume, measured with the same bucket or shovel for each material. It is a rule of thumb rather than a figure from a standard, but it lands in the same range as ACI's mixtures above, and it is fine for small non-structural pours such as paths, steps and post footings. For anything structural, use a specified mix or ready-mix.
Using bagged premix instead
For most small jobs, bagged concrete mix is easier: the cement, sand and gravel are already proportioned, so you only add water. Yields and water amounts are printed on the bag. These are the figures from Quikrete's data sheet for its standard Concrete Mix (No. 1101); bags per cubic yard is 27 ft³ ÷ yield:
How much water to add
More water makes the mix easier to work but lowers its strength. In ACI's table of typical values (ACI PRC-211.1-22, Table 5.3.4), a water-cement ratio of 0.57 by weight gives about 4,000 psi at 28 days, 0.68 about 3,000 psi and 0.82 about 2,000 psi (concrete without air entrainment).
What to aim for: Quikrete's instructions say to add water as needed until "a stiff, moldable consistency is achieved", with no dry pockets of material and no standing puddles of water. ACI's test for small jobs is that good concrete "slides, not runs, off a shovel". With bagged mix, stay within the maximum water printed on the bag.
Mixing sequence
Quikrete's hand-mixing steps for bagged concrete mix:
- Empty the bag into a suitable mixing container
- Add the starting water for your bag size (about 6 pints for an 80 lb bag)
- Work the mix with a shovel, rake or hoe, adding water as needed until it reaches a stiff, moldable consistency
- Make sure there are no dry pockets of material and no standing puddles of water
With Fast-Setting Concrete Mix, Quikrete says to mix only as much as you can place in 20 minutes.
Sizing up the job
No code or manufacturer sets a maximum volume for hand mixing, so judge it by the numbers. Each 80 lb bag of Quikrete Concrete Mix makes only about 0.60 ft³, so a cubic yard takes 45 bags — 3,600 lb of dry mix to lift and mix. If you hire a drum mixer instead, Quikrete says to allow at least 1 ft³ of mixer capacity for each 80 lb bag mixed at one time.
After the pour
Concrete hardens by a chemical reaction with water (hydration), not by drying out. Quikrete's data sheet says curing should start as soon as possible and continue for 5 days in warm weather (70 °F / 21 °C or higher) or 7 days in cooler weather (50–70 °F / 10–21 °C). Methods it lists include a cure-and-seal compound, wet burlap, plastic sheeting or waterproof paper, or keeping the surface wet with a lawn sprinkler. It also says to protect the concrete from freezing for the first 48 hours, using plastic sheeting and insulation blankets if temperatures are expected to fall below 32 °F (0 °C). Our concrete curing time guide covers when you can walk, build or drive on it.
Putting it together
Before mixing, work out how much concrete you actually need. Our concrete calculator gives volume in m³ and cubic yards with waste included, and our concrete bag calculator converts that directly into bag counts for 40lb, 60lb, and 80lb bags.
FAQ
What is the correct mix ratio for concrete by hand?
There is no single correct ratio. The American Concrete Institute's guide to proportioning concrete (ACI PRC-211.1-22, Table A.7.1) gives starting mixtures for small jobs by weight. For 3/4-inch gravel and concrete without air entrainment, its Mixture B is 23 lb cement, 47 lb sand and 64 lb gravel per cubic foot of concrete — about 1 : 2 : 2¾ by weight. On site this is commonly simplified to 1 part cement, 2 parts sand and 3 parts gravel by volume (the 1:2:3 rule of thumb), which is fine for small non-structural pours. Add just enough water for a workable consistency; ACI describes a good consistency as concrete that slides, not runs, off a shovel. For structural work, follow your local building code or an engineer's specification.
Is it mixing cement or mixing concrete?
Cement is only the grey powder that binds everything together — it is never used on its own. Mix cement with sand, gravel and water and you get concrete (for slabs, posts and footings). Mix sand and water with a mortar binder — portland cement and lime, or a masonry or mortar cement — and you get mortar (for laying bricks and blocks). 'Mixing cement by hand' almost always means mixing concrete.
How much water do I add to an 80 lb bag of concrete?
Quikrete's data sheet for its Concrete Mix calls for about 6 pints (3 quarts, 2.8 litres) of water per 80 lb bag to start, then more as needed until the mix is stiff and moldable. The final amount should be about 6 to 9 pints (2.8 to 4.3 litres) per 80 lb bag. Other brands and products differ — always follow the instructions printed on your bag.
How much water should I add to site-mixed concrete?
ACI's procedure for small jobs is to add just enough water to produce a workable consistency — concrete that slides, not runs, off a shovel. Extra water costs strength: in ACI's table of typical values (ACI PRC-211.1-22, Table 5.3.4), a water-cement ratio of 0.57 by weight corresponds to about 4,000 psi at 28 days, while 0.68 gives about 3,000 psi (concrete without air entrainment).
How much concrete can I mix by hand?
No code or manufacturer sets a maximum. Quikrete's hand-mixing instructions work bag by bag, and each 80 lb bag of its Concrete Mix makes only about 0.60 cubic feet — so one cubic yard is 45 bags, or 3,600 lb of dry mix. If you hire a drum mixer instead, Quikrete says to allow at least 1 cubic foot of mixer capacity for each 80 lb bag mixed at one time.
How long does hand-mixed concrete take to set?
It depends on the product and the weather. Quikrete's Fast-Setting Concrete Mix sets in 20 to 40 minutes; for its standard Concrete Mix, Quikrete says to wait 24 hours before a post set in it is put under any strain. Strength keeps rising for weeks: Quikrete's Concrete Mix reaches a typical 2,500 psi at 7 days and 4,000 psi at 28 days. The 28-day result is the conventional value accepted as concrete's compressive strength (ACI PRC-211.1-22).