[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"glossary:en":3,"tool-content:en:concrete-calculator":4,"published-tools-en":63},[],{"id":5,"documentId":6,"slug":7,"intro":8,"howTo":9,"longContent":10,"createdAt":11,"updatedAt":12,"publishedAt":13,"locale":14,"name":15,"faq":16,"examples":37,"category":38,"seo":47,"localizations":52,"metaTitle":49,"metaDescription":50},108,"rj9lphz9puejulmbhx1ma5lf","concrete-calculator","\u003Cp>This \u003Cstrong>concrete calculator\u003C\u002Fstrong> tells you how much concrete you need for a slab, a column or a footing. Enter the dimensions in metric or imperial units and you get the volume in cubic meters and cubic yards, plus the number of bags to buy. A \u003Cstrong>4 x 3 m slab\u003C\u002Fstrong> poured 10 cm thick needs 1.2 m³, for example.\u003C\u002Fp>","\u003Col>\u003Cli>Pick the shape you are pouring: slab, column or footing.\u003C\u002Fli>\u003Cli>Choose metric or imperial units, then enter the dimensions (thickness is in inches in imperial mode).\u003C\u002Fli>\u003Cli>Set the quantity if you pour several identical elements, like 6 fence post footings.\u003C\u002Fli>\u003Cli>Read the volume in m³ and yd³, the recommended 10% margin and the bag count.\u003C\u002Fli>\u003C\u002Fol>","\u003Ch2>How the concrete calculator works\u003C\u002Fh2>\n\u003Cp>The \u003Cstrong>concrete calculator\u003C\u002Fstrong> covers the three shapes behind most home pours. Each one runs on a simple geometric formula:\u003C\u002Fp>\n\u003Cul>\n\u003Cli>\u003Cstrong>Slab and footing:\u003C\u002Fstrong> length x width x thickness\u003C\u002Fli>\n\u003Cli>\u003Cstrong>Column:\u003C\u002Fstrong> pi x (diameter \u002F 2)² x height\u003C\u002Fli>\n\u003C\u002Ful>\n\u003Cp>In metric mode every field is in meters, so a 10 cm slab goes in as 0.1. In imperial mode length, width, diameter and height are in feet, while thickness stays in inches. The calculator turns those inches into feet for you, which is where most hand estimates fall apart.\u003C\u002Fp>\n\u003Ch2 id=\"worked-example\">A worked example\u003C\u002Fh2>\n\u003Cp>Say you are pouring a patio slab of 4 m by 3 m at 10 cm thick. The volume is 4 x 3 x 0.1 = \u003Cstrong>1.2 m³\u003C\u002Fstrong>, about 1.57 cubic yards. With the recommended 10% margin you would order 1.32 m³. In bagged concrete that comes to \u003Cstrong>110 bags\u003C\u002Fstrong> of 25 kg, a clear sign that ready-mix delivery makes more sense at this size.\u003C\u002Fp>\n\u003Cp>The same math holds in imperial units. A 12 x 10 ft slab at 4 inches is 12 x 10 x 0.333 = 40 cubic feet, or 1.48 cubic yards, since a cubic yard is \u003Cstrong>27 cubic feet\u003C\u002Fstrong>.\u003C\u002Fp>\n\u003Ch2 id=\"bags-or-ready-mix\">Bags or a ready-mix truck?\u003C\u002Fh2>\n\u003Cp>The calculator shows both bag counts because the break-even point comes up fast. One 25 kg bag yields roughly \u003Cstrong>0.011 m³\u003C\u002Fstrong> of concrete once mixed, and a US 80 lb bag about 0.60 ft³ (0.017 m³).\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\u003Ctr>\u003Cth>Volume needed\u003C\u002Fth>\u003Cth>25 kg bags\u003C\u002Fth>\u003Cth>80 lb bags\u003C\u002Fth>\u003Cth>Best option\u003C\u002Fth>\u003C\u002Ftr>\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\u003Ctd>0.1 m³ (small footing)\u003C\u002Ftd>\u003Ctd>10\u003C\u002Ftd>\u003Ctd>6\u003C\u002Ftd>\u003Ctd>Bags\u003C\u002Ftd>\u003C\u002Ftr>\n\u003Ctr>\u003Ctd>0.5 m³ (short walkway)\u003C\u002Ftd>\u003Ctd>46\u003C\u002Ftd>\u003Ctd>30\u003C\u002Ftd>\u003Ctd>Bags, with help\u003C\u002Ftd>\u003C\u002Ftr>\n\u003Ctr>\u003Ctd>1.2 m³ (4 x 3 m slab)\u003C\u002Ftd>\u003Ctd>110\u003C\u002Ftd>\u003Ctd>71\u003C\u002Ftd>\u003Ctd>Ready-mix truck\u003C\u002Ftd>\u003C\u002Ftr>\n\u003Ctr>\u003Ctd>3 m³ (driveway)\u003C\u002Ftd>\u003Ctd>273\u003C\u002Ftd>\u003Ctd>177\u003C\u002Ftd>\u003Ctd>Ready-mix truck\u003C\u002Ftd>\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Cp>Past roughly \u003Cstrong>one cubic yard\u003C\u002Fstrong> (0.76 m³), mixing by hand turns into a race against setting time. Ready-mix costs more per cubic meter, but it arrives as one consistent batch.\u003C\u002Fp>\n\u003Ch2 id=\"why-the-margin\">Why the 10% margin matters\u003C\u002Fh2>\n\u003Cp>Ground is never perfectly level, forms flex a little, and some concrete always clings to the mixer or the wheelbarrow. Order the exact computed volume and you finish the pour short, then pay far more for a second small delivery than the extra 10% would have cost. The calculator lists the margin on its own line so you can decide, and for slabs on grade you should almost always take it.\u003C\u002Fp>\n\u003Ch3>Typical slab thicknesses\u003C\u002Fh3>\n\u003Cp>A garden shed base works at 8 cm (3 in), a patio or garage floor at \u003Cstrong>10 cm\u003C\u002Fstrong> (4 in), and a driveway that carries vehicles at 12 to 15 cm (5 to 6 in). Doubling the thickness doubles the volume, so check this value before anything else.\u003C\u002Fp>","2026-07-17T11:47:07.854Z","2026-07-17T12:52:55.347Z","2026-07-17T12:52:56.423Z","en","Concrete Calculator",[17,21,25,29,33],{"id":18,"question":19,"answer":20},609,"How much concrete do I need for a 12 x 10 ft slab?","\u003Cp>At the standard 4 inch thickness, a 12 x 10 ft slab needs 40 cubic feet, which is 1.48 cubic yards or about 1.13 m³. Add the 10% margin and you order \u003Cstrong>1.63 cubic yards\u003C\u002Fstrong>. That volume calls for a ready-mix truck rather than bags.\u003C\u002Fp>",{"id":22,"question":23,"answer":24},610,"How many 25 kg bags of concrete make 1 m³?","\u003Cp>One 25 kg bag yields roughly 0.011 m³ once mixed with water, so a full cubic meter takes about \u003Cstrong>91 bags\u003C\u002Fstrong>. That is over 2.2 tonnes to carry and mix by hand, which is why truck delivery starts to pay off around 1 m³.\u003C\u002Fp>",{"id":26,"question":27,"answer":28},611,"Should I include the 10% margin in my order?","\u003Cp>Yes, in almost every case. The margin absorbs uneven ground, slight over-digging and the concrete lost to mixing. Run out mid-pour and you leave a cold joint that weakens the slab, on top of an expensive second delivery.\u003C\u002Fp>",{"id":30,"question":31,"answer":32},612,"How thick should a concrete slab be?","\u003Cp>Use 8 cm (3 in) for a light shed base, \u003Cstrong>10 cm (4 in)\u003C\u002Fstrong> for patios and garage floors, and 12 to 15 cm (5 to 6 in) for driveways. When you are unsure, go thicker, since the extra cost is small next to replacing a cracked slab.\u003C\u002Fp>",{"id":34,"question":35,"answer":36},613,"How do I calculate concrete for several identical footings?","\u003Cp>Enter the dimensions of one footing, then set the quantity field. Six footings of 0.5 x 0.5 m at 25 cm deep come to 6 x 0.0625 = 0.375 m³, or about 35 bags of 25 kg.\u003C\u002Fp>",[],{"id":39,"documentId":40,"uid":41,"name":42,"tagline":43,"hubContent":44,"createdAt":45,"updatedAt":45,"publishedAt":46,"locale":14},15,"s8cujbpmiszotf6zdbotc2p0","math","Math","Calculators for school, work and everyday numbers","\u003Cp>Every calculator in this category computes live as you type and shows the formula behind the result. Grades, percentages, fractions, ratios or volumes: you see the answer and the reasoning, so you can trust the number you copy. Each tool also documents its edge cases, because a calculator you cannot verify is just a guess with confidence.\u003C\u002Fp>","2026-07-17T11:46:54.883Z","2026-07-17T12:01:48.544Z",{"id":48,"metaTitle":49,"metaDescription":50,"keywords":51,"metaRobots":51,"structuredData":51,"metaViewport":51,"canonicalURL":51},147,"Concrete Calculator: Slabs, Columns, Footings","Free concrete calculator for slabs, columns and footings. Get cubic meters, cubic yards, a 10% safety margin and the exact number of bags to buy.",null,[53],{"id":54,"documentId":6,"slug":7,"intro":55,"howTo":56,"longContent":57,"createdAt":58,"updatedAt":59,"publishedAt":60,"locale":61,"name":62},168,"\u003Cp>Cet outil de \u003Cstrong>calcul béton\u003C\u002Fstrong> vous donne le volume nécessaire pour une dalle, un poteau ou une semelle. Entrez les dimensions en unités métriques ou impériales et vous obtenez le volume en mètres cubes et en yards cubes, avec le nombre de sacs à prévoir. Une dalle de \u003Cstrong>4 x 3 m\u003C\u002Fstrong> coulée sur 10 cm demande par exemple 1,2 m³.\u003C\u002Fp>","\u003Col>\u003Cli>Choisissez la forme à couler : dalle, poteau ou semelle.\u003C\u002Fli>\u003Cli>Sélectionnez les unités métriques ou impériales, puis entrez les dimensions (l'épaisseur se saisit en pouces en mode impérial).\u003C\u002Fli>\u003Cli>Indiquez la quantité si vous coulez plusieurs éléments identiques, par exemple 6 plots de clôture.\u003C\u002Fli>\u003Cli>Lisez le volume en m³ et yd³, la marge de 10 % conseillée et le nombre de sacs.\u003C\u002Fli>\u003C\u002Fol>","\u003Ch2>Comment fonctionne le calcul béton\u003C\u002Fh2>\n\u003Cp>Le \u003Cstrong>calcul béton\u003C\u002Fstrong> couvre les trois formes qui reviennent le plus chez un particulier, chacune reposant sur une formule géométrique simple :\u003C\u002Fp>\n\u003Cul>\n\u003Cli>\u003Cstrong>Dalle et semelle :\u003C\u002Fstrong> longueur x largeur x épaisseur\u003C\u002Fli>\n\u003Cli>\u003Cstrong>Poteau :\u003C\u002Fstrong> pi x (diamètre \u002F 2)² x hauteur\u003C\u002Fli>\n\u003C\u002Ful>\n\u003Cp>En mode métrique, tous les champs sont en mètres, donc une dalle de 10 cm se saisit 0,1. En mode impérial, longueur, largeur, diamètre et hauteur passent en pieds tandis que l'épaisseur reste en pouces. La conversion pouces vers pieds se fait automatiquement, là où la plupart des estimations à la main dérapent.\u003C\u002Fp>\n\u003Ch2 id=\"exemple-chiffre\">Un exemple chiffré\u003C\u002Fh2>\n\u003Cp>Prenons une dalle de terrasse de 4 m sur 3 m, coulée sur 10 cm. Le volume vaut 4 x 3 x 0,1 = \u003Cstrong>1,2 m³\u003C\u002Fstrong>, soit environ 1,57 yard cube. Avec la marge de 10 % conseillée, commandez 1,32 m³. En sacs, cela fait \u003Cstrong>110 sacs\u003C\u002Fstrong> de 25 kg, un signe clair qu'un camion toupie s'impose pour une dalle de cette taille.\u003C\u002Fp>\n\u003Cp>Pour un poteau de 30 cm de diamètre et 2,40 m de haut, le calcul donne pi x 0,15² x 2,4 = 0,17 m³, soit 16 sacs de 25 kg, un volume où le gâchage à la bétonnière reste tout à fait raisonnable.\u003C\u002Fp>\n\u003Ch2 id=\"sacs-ou-toupie\">Sacs ou camion toupie ?\u003C\u002Fh2>\n\u003Cp>Le calculateur affiche les deux équivalents en sacs parce que le point de bascule arrive vite. Un sac de 25 kg produit environ \u003Cstrong>0,011 m³\u003C\u002Fstrong> de béton une fois gâché, un sac US de 80 lb environ 0,017 m³.\u003C\u002Fp>\n\u003Ctable>\n\u003Cthead>\u003Ctr>\u003Cth>Volume nécessaire\u003C\u002Fth>\u003Cth>Sacs de 25 kg\u003C\u002Fth>\u003Cth>Meilleure option\u003C\u002Fth>\u003C\u002Ftr>\u003C\u002Fthead>\n\u003Ctbody>\n\u003Ctr>\u003Ctd>0,1 m³ (petite semelle)\u003C\u002Ftd>\u003Ctd>10\u003C\u002Ftd>\u003Ctd>Sacs\u003C\u002Ftd>\u003C\u002Ftr>\n\u003Ctr>\u003Ctd>0,5 m³ (allée courte)\u003C\u002Ftd>\u003Ctd>46\u003C\u002Ftd>\u003Ctd>Sacs, à deux\u003C\u002Ftd>\u003C\u002Ftr>\n\u003Ctr>\u003Ctd>1,2 m³ (dalle 4 x 3 m)\u003C\u002Ftd>\u003Ctd>110\u003C\u002Ftd>\u003Ctd>Camion toupie\u003C\u002Ftd>\u003C\u002Ftr>\n\u003Ctr>\u003Ctd>3 m³ (descente de garage)\u003C\u002Ftd>\u003Ctd>273\u003C\u002Ftd>\u003Ctd>Camion toupie\u003C\u002Ftd>\u003C\u002Ftr>\n\u003C\u002Ftbody>\n\u003C\u002Ftable>\n\u003Cp>Au-delà d'environ \u003Cstrong>0,8 m³\u003C\u002Fstrong>, gâcher à la main devient une course contre la prise du béton. La toupie coûte plus cher au mètre cube tout en livrant un béton homogène en une seule fois.\u003C\u002Fp>\n\u003Ch2 id=\"pourquoi-la-marge\">Pourquoi prévoir 10 % de marge\u003C\u002Fh2>\n\u003Cp>Un sol n'est jamais parfaitement plan, les coffrages fléchissent un peu et il reste toujours du béton dans la bétonnière ou la brouette. Commander le volume exact calculé revient à finir le coulage à sec. Une seconde livraison de complément coûte alors bien plus cher que les 10 % en plus. La marge apparaît sur sa propre ligne pour vous laisser décider, un choix que vous aurez presque toujours intérêt à faire sur une dalle sur terre-plein.\u003C\u002Fp>\n\u003Ch3>Épaisseurs courantes de dalle\u003C\u002Fh3>\n\u003Cp>Un abri de jardin se contente de 8 cm, une terrasse ou un sol de garage demande \u003Cstrong>10 cm\u003C\u002Fstrong> et une allée carrossable réclame 12 à 15 cm. Doubler l'épaisseur double le volume, donc vérifiez cette valeur avant tout le reste.\u003C\u002Fp>","2026-07-17T11:47:08.673Z","2026-07-17T12:54:54.713Z","2026-07-17T12:54:55.803Z","fr","Calcul béton",{"slugs":64},[65,66,67,7,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84],"age-calculator","average-calculator","cd-calculator","cursive-font-generator","date-calculator","fantasy-name-generator","final-grade-calculator","fraction-calculator","glitch-text-generator","gpa-calculator","grade-calculator","hex-converter","hours-calculator","interest-calculator","military-time-converter","roman-numeral-converter","password-generator","kg-to-lbs-converter","binary-converter","celsius-to-fahrenheit-converter"]