{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"concrete-mix-ratio"},"result":{"entity_type":"calculator","id":"concrete-mix-ratio","calculator_id":"concrete-mix-ratio","canonical_url":"https://tttkmbb.com/construction/concrete-mix-ratio","name":"Concrete Mix Ratio Calculator","title":"Concrete Mix Ratio Calculator – Cement Bags, Sand, Aggregate and Water for a Nominal Mix (1:2:4, 1:1.5:3, 1:1:2)","category":"construction","category_name":"Construction & Home","tool_name":"calculate_concrete_mix_quantities","featured_mcp_tool":false,"description":"Converts a wet concrete volume into the dry materials for a nominal volumetric mix: the dry volume (× 1.54 for voids and shrinkage) is split by the cement : sand : aggregate parts, converted to mass with bulk densities (cement 1,440, sand 1,600, aggregate 1,450 kg/m³), cement is expressed in bags and water follows the water-cement ratio.","use_when":"You are site-mixing concrete by volume batching and need the cement bags, sand, coarse aggregate and water for a given volume at a nominal mix such as 1:2:4 (M15) or 1:1.5:3 (M20).","do_not_use_when":"You are ordering ready-mix or bagged premix (use concrete-slab or concrete-footing for volumes and bags), or you need a designed mix for a specified strength with admixtures (a design mix from the supplier's laboratory).","inputs":[{"name":"wet_concrete_volume_m3","label":"Wet concrete volume","type":"number","unit":"m³","required":true,"max":10000,"exclusive_min":0,"description":"Volume of placed (compacted) concrete in cubic metres, waste included.","example":1},{"name":"mix_ratio","label":"Mix ratio","type":"enum","required":false,"default":"1_2_4","values":[{"value":"1_3_6","label":"1 : 3 : 6 (M10)","aliases":["1:3:6","m10"]},{"value":"1_2_4","label":"1 : 2 : 4 (M15)","aliases":["1:2:4","m15"]},{"value":"1_1_5_3","label":"1 : 1.5 : 3 (M20)","aliases":["1:1.5:3","m20"]},{"value":"1_1_2","label":"1 : 1 : 2 (M25)","aliases":["1:1:2","m25"]},{"value":"custom","label":"Custom (cement_parts : sand_parts : aggregate_parts)"}],"description":"Nominal cement : sand : coarse-aggregate proportions by volume, with the approximate IS 456 grade they correspond to.","example":"1_2_4"},{"name":"cement_parts","label":"Cement parts","type":"number","required":false,"max":10,"exclusive_min":0,"description":"Cement parts by volume for mix_ratio = custom (usually 1)."},{"name":"sand_parts","label":"Sand parts","type":"number","required":false,"min":0,"max":20,"description":"Fine-aggregate (sand) parts by volume for mix_ratio = custom."},{"name":"aggregate_parts","label":"Aggregate parts","type":"number","required":false,"min":0,"max":20,"description":"Coarse-aggregate parts by volume for mix_ratio = custom."},{"name":"dry_volume_factor","label":"Dry volume factor","type":"number","required":false,"default":1.54,"min":1,"max":2,"description":"Ratio of loose dry materials to compacted wet concrete; 1.52–1.57 is the usual allowance, 1.54 is the common estimating value.","example":1.54},{"name":"cement_density_kg_m3","label":"Cement bulk density","type":"number","unit":"kg/m³","required":false,"default":1440,"max":3000,"exclusive_min":0,"description":"Loose bulk density of cement (1,440 kg/m³, i.e. one 50 kg bag ≈ 0.0347 m³ ≈ 1.226 ft³).","example":1440},{"name":"bag_kg","label":"Cement bag size","type":"number","unit":"kg","required":false,"default":50,"max":100,"exclusive_min":0,"description":"Mass of one cement bag: 50 kg (India, most of the world), 25 kg (UK/EU), 40 kg (Australia), 42.6 kg (US 94 lb bag).","example":50},{"name":"water_cement_ratio","label":"Water-cement ratio","type":"number","required":false,"default":0.5,"min":0.3,"max":1,"description":"Mass of water per mass of cement; 0.45–0.55 is typical for nominal mixes (lower gives higher strength but stiffer concrete).","example":0.5},{"name":"sand_density_kg_m3","label":"Sand bulk density","type":"number","unit":"kg/m³","required":false,"default":1600,"max":3000,"exclusive_min":0,"description":"Loose bulk density of dry sand.","example":1600},{"name":"aggregate_density_kg_m3","label":"Aggregate bulk density","type":"number","unit":"kg/m³","required":false,"default":1450,"max":3000,"exclusive_min":0,"description":"Loose bulk density of coarse aggregate (20 mm crushed stone ≈ 1,450 kg/m³).","example":1450}],"outputs":[{"name":"mix_ratio_used","label":"Mix ratio","type":"string","decimals":4,"description":"Cement : sand : aggregate parts applied."},{"name":"dry_volume_m3","label":"Dry materials volume","type":"number","unit":"m³","decimals":3,"description":"wet_concrete_volume × dry_volume_factor."},{"name":"cement_m3","label":"Cement volume","type":"number","unit":"m³","decimals":3,"description":"dry_volume × cement_parts / total_parts."},{"name":"cement_kg","label":"Cement","type":"number","unit":"kg","decimals":1,"description":"cement_m3 × cement_density."},{"name":"cement_bags","label":"Cement bags","type":"integer","decimals":4,"description":"ceil(cement_kg / bag_kg)."},{"name":"sand_m3","label":"Sand volume","type":"number","unit":"m³","decimals":3,"description":"dry_volume × sand_parts / total_parts."},{"name":"sand_kg","label":"Sand","type":"number","unit":"kg","decimals":0,"description":"sand_m3 × sand_density."},{"name":"aggregate_m3","label":"Coarse aggregate volume","type":"number","unit":"m³","decimals":3,"description":"dry_volume × aggregate_parts / total_parts."},{"name":"aggregate_kg","label":"Coarse aggregate","type":"number","unit":"kg","decimals":0,"description":"aggregate_m3 × aggregate_density."},{"name":"water_liters","label":"Water","type":"number","unit":"L","decimals":1,"description":"water_cement_ratio × cement_kg (1 kg of water = 1 L)."}],"input_schema":{"type":"object","properties":{"wet_concrete_volume_m3":{"description":"Volume of placed (compacted) concrete in cubic metres, waste included. Unit: m³.","type":"number","maximum":10000,"exclusiveMinimum":0,"examples":[1],"x-unit":"m³"},"mix_ratio":{"description":"Nominal cement : sand : coarse-aggregate proportions by volume, with the approximate IS 456 grade they correspond to.","type":"string","enum":["1_3_6","1_2_4","1_1_5_3","1_1_2","custom"],"default":"1_2_4","examples":["1_2_4"]},"cement_parts":{"description":"Cement parts by volume for mix_ratio = custom (usually 1).","type":"number","maximum":10,"exclusiveMinimum":0},"sand_parts":{"description":"Fine-aggregate (sand) parts by volume for mix_ratio = custom.","type":"number","minimum":0,"maximum":20},"aggregate_parts":{"description":"Coarse-aggregate parts by volume for mix_ratio = custom.","type":"number","minimum":0,"maximum":20},"dry_volume_factor":{"description":"Ratio of loose dry materials to compacted wet concrete; 1.52–1.57 is the usual allowance, 1.54 is the common estimating value.","type":"number","minimum":1,"maximum":2,"default":1.54,"examples":[1.54]},"cement_density_kg_m3":{"description":"Loose bulk density of cement (1,440 kg/m³, i.e. one 50 kg bag ≈ 0.0347 m³ ≈ 1.226 ft³). Unit: kg/m³.","type":"number","maximum":3000,"exclusiveMinimum":0,"default":1440,"examples":[1440],"x-unit":"kg/m³"},"bag_kg":{"description":"Mass of one cement bag: 50 kg (India, most of the world), 25 kg (UK/EU), 40 kg (Australia), 42.6 kg (US 94 lb bag). Unit: kg.","type":"number","maximum":100,"exclusiveMinimum":0,"default":50,"examples":[50],"x-unit":"kg"},"water_cement_ratio":{"description":"Mass of water per mass of cement; 0.45–0.55 is typical for nominal mixes (lower gives higher strength but stiffer concrete).","type":"number","minimum":0.3,"maximum":1,"default":0.5,"examples":[0.5]},"sand_density_kg_m3":{"description":"Loose bulk density of dry sand. Unit: kg/m³.","type":"number","maximum":3000,"exclusiveMinimum":0,"default":1600,"examples":[1600],"x-unit":"kg/m³"},"aggregate_density_kg_m3":{"description":"Loose bulk density of coarse aggregate (20 mm crushed stone ≈ 1,450 kg/m³). Unit: kg/m³.","type":"number","maximum":3000,"exclusiveMinimum":0,"default":1450,"examples":[1450],"x-unit":"kg/m³"}},"additionalProperties":false,"required":["wet_concrete_volume_m3"]},"output_schema":{"type":"object","properties":{"mix_ratio_used":{"description":"Cement : sand : aggregate parts applied.","type":"string"},"dry_volume_m3":{"description":"wet_concrete_volume × dry_volume_factor. Unit: m³.","type":"number","x-unit":"m³"},"cement_m3":{"description":"dry_volume × cement_parts / total_parts. Unit: m³.","type":"number","x-unit":"m³"},"cement_kg":{"description":"cement_m3 × cement_density. Unit: kg.","type":"number","x-unit":"kg"},"cement_bags":{"description":"ceil(cement_kg / bag_kg).","type":"integer"},"sand_m3":{"description":"dry_volume × sand_parts / total_parts. Unit: m³.","type":"number","x-unit":"m³"},"sand_kg":{"description":"sand_m3 × sand_density. Unit: kg.","type":"number","x-unit":"kg"},"aggregate_m3":{"description":"dry_volume × aggregate_parts / total_parts. Unit: m³.","type":"number","x-unit":"m³"},"aggregate_kg":{"description":"aggregate_m3 × aggregate_density. Unit: kg.","type":"number","x-unit":"kg"},"water_liters":{"description":"water_cement_ratio × cement_kg (1 kg of water = 1 L). Unit: L.","type":"number","x-unit":"L"}}},"formula":"dry_volume = wet_concrete_volume_m3 × dry_volume_factor; total_parts = cement + sand + aggregate; cement_m3 = dry_volume × cement_parts / total_parts (sand and aggregate likewise); cement_kg = cement_m3 × 1440; cement_bags = ceil(cement_kg / bag_kg); sand_kg = sand_m3 × 1600; aggregate_kg = aggregate_m3 × 1450; water_L = water_cement_ratio × cement_kg.","method":"Volume-batching (nominal mix) method used for small site-mixed pours; the 1.54 factor and the bulk densities are estimating conventions, and nominal mixes correspond only approximately to the IS 456 grades (M10–M25). Aggregate moisture, bulking of damp sand and wastage are not included; add 3–5 %.","sources":[{"name":"Wikipedia – Concrete (mix design)","url":"https://en.wikipedia.org/wiki/Concrete","type":"reference","retrieved_at":"2026-09-24"},{"name":"Wikipedia – Types of concrete","url":"https://en.wikipedia.org/wiki/Types_of_concrete","type":"reference","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"1 m³ at 1:2:4, 50 kg bags, w/c 0.5","inputs":{"wet_concrete_volume_m3":1,"mix_ratio":"1_2_4","dry_volume_factor":1.54,"cement_density_kg_m3":1440,"bag_kg":50,"water_cement_ratio":0.5},"expected":{"dry_volume_m3":1.54,"cement_m3":0.22,"cement_kg":316.8,"cement_bags":7,"sand_m3":0.44,"sand_kg":704,"aggregate_m3":0.88,"aggregate_kg":1276,"water_liters":158.4,"mix_ratio_used":"1 : 2 : 4"},"url":"https://tttkmbb.com/api/v1/calculate/concrete-mix-ratio?wet_concrete_volume_m3=1&mix_ratio=1_2_4&dry_volume_factor=1.54&cement_density_kg_m3=1440&bag_kg=50&water_cement_ratio=0.5"},{"name":"2.5 m³ at 1:1.5:3 (M20), 25 kg bags, w/c 0.45","inputs":{"wet_concrete_volume_m3":2.5,"mix_ratio":"1_1_5_3","bag_kg":25,"water_cement_ratio":0.45},"expected":{"dry_volume_m3":3.85,"cement_m3":0.7,"cement_kg":1008,"cement_bags":41,"sand_m3":1.05,"sand_kg":1680,"aggregate_m3":2.1,"aggregate_kg":3045,"water_liters":453.6},"url":"https://tttkmbb.com/api/v1/calculate/concrete-mix-ratio?wet_concrete_volume_m3=2.5&mix_ratio=1_1_5_3&bag_kg=25&water_cement_ratio=0.45"}],"faq":[{"q":"Why multiply by 1.54?","a":"Loose cement, sand and stone contain voids that are filled when the mix is compacted, so about 1.54 m³ of dry materials produce 1 m³ of concrete; some references use 1.52–1.57."},{"q":"How many cement bags per cubic metre?","a":"About 6.3 bags of 50 kg (317 kg) for 1:2:4 and 8 bags (403 kg) for 1:1.5:3; bags are rounded up."},{"q":"Is 1:2:4 the same as M15?","a":"Approximately: IS 456 lists 1:2:4 as the nominal mix for M15 and 1:1.5:3 for M20, but the actual strength depends on the water-cement ratio, aggregate and curing, so a design mix is needed where a specific strength must be guaranteed."}],"tags":["concrete mix ratio","1:2:4 concrete","cement bags per m3","m20 concrete","sand and aggregate quantity","nominal mix"],"related":[{"calculator_id":"concrete-slab","reason":"Wet volume of a slab to feed into this calculator."},{"calculator_id":"concrete-footing","reason":"Wet volume of footings and piers."},{"calculator_id":"gravel","reason":"Aggregate weight and volume conversions."}],"links":{"html":"https://tttkmbb.com/construction/concrete-mix-ratio","markdown":"https://tttkmbb.com/construction/concrete-mix-ratio.md","json":"https://tttkmbb.com/construction/concrete-mix-ratio.json","api":"https://tttkmbb.com/api/v1/calculate/concrete-mix-ratio","schema":"https://tttkmbb.com/api/v1/calculators/concrete-mix-ratio","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T03:49:31Z","next_actions":[{"tool":"run_calculator","calculator_id":"concrete-mix-ratio","reason":"Run Concrete Mix Ratio Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/construction/concrete-mix-ratio.md"}}