🔨 Construction et bricolage

Calculateur de Volume de Béton et Sacs

Calculez le volume de béton (m³ / yd³) pour dalles, semelles, colonnes, escaliers et trous de poteaux, plus le nombre de sacs de mélange de 40lb / 60lb / 80lb / 25kg à acheter. 10 % de perte incluse.

Forme

Unités

Longueur ft

Largeur ft

Profondeur in

Diamètre in

Hauteur / profondeur ft

Quantité

Nombre de marches

Hauteur par marche in

Giron par marche in

Largeur in

Béton nécessaire

0.00 yd³

0.00 m³ · 0.0 ft³

Taille du sac	Sacs nécessaires

Comment fonctionne le calcul

Dalle / semelle : volume = longueur × largeur × profondeur. Colonne / trou de poteau : volume = π × rayon² × hauteur. Escaliers : approximé comme une somme de blocs cumulés — la marche i vaut hauteur×(i×giron)×largeur, additionné sur toutes les marches.

Rendement des sacs : 40 lb → 0.011 yd³ (0.30 ft³), 60 lb → 0.017 yd³ (0.45 ft³), 80 lb → 0.022 yd³ (0.60 ft³), 25 kg → 0.0125 m³, 30 kg → 0.015 m³.

La marge de 10 % pour les pertes tient compte d'un support inégal, du gaspillage et d'une légère surcommande — une bonne pratique pour les coulages résidentiels.

Comment fonctionne le calcul

Three geometries share one output. Slab / footing is length × width × depth. Column / post hole is π × radius² × height, multiplied by your quantity. Stairs are summed as cumulative blocks: step i contributes rise × (i × run) × width, added across every step, which is how a poured monolithic flight actually stacks. Everything is computed in cubic feet, multiplied by 1.10 while the waste toggle is on, then reported as cubic yards (÷ 27), cubic metres (× 0.0283168) and cubic feet.

Watch the unit pairing: in imperial mode the large dimensions are feet while depth, diameter, rise, run and stair width are inches; in metric mode they become metres and centimetres. The default slab is 10 × 10 ft at 4 in deep. The bag table converts your volume against fixed yields — 40 lb at 0.30 ft³, 60 lb at 0.45 ft³, 80 lb at 0.60 ft³, plus 25 kg and 30 kg European sizes — and always rounds up to whole bags.

The 10 percent waste factor is a residential rule of thumb covering spillage and an uneven sub-grade; it is not a substitute for measuring an over-dug footing trench, which can swallow far more. Rebar, mesh and embedded post volume are not deducted, and stair side walls, landings and open risers are not modelled at all. For anything you are ordering ready-mix against, treat the figure as a shopping estimate and confirm with your supplier before the truck is booked.

FAQ

How many 80 lb bags of concrete make a cubic yard?

About 46. The tool uses a yield of 0.022 cubic yards, or 0.60 cubic feet, per 80 lb bag, so a full yard takes 45.5 bags and the table rounds that up. Sixty pound bags need roughly 60, and 40 lb bags about 91.

Should I leave the +10% waste toggle on?

For most residential pours, yes. It is on by default and multiplies the raw volume by 1.10 to cover spillage, an uneven base and slight over-ordering. Switch it off only when you want the exact geometric volume, for example when checking a supplier's own quote.

How do I calculate concrete for a round post hole?

Choose the Column / post hole shape. Enter the hole diameter in inches, the depth in feet, and set Quantity to the number of holes. The tool applies π × radius² × height per hole and multiplies through, so all your posts come out in one figure.

Does the stairs mode include the side walls or a landing?

No. Stairs are summed purely as stacked rectangular blocks, step by step. Cheek walls, a top landing, a thickened base and any hollow or backfilled void underneath are not included, so a real flight with side walls will need meaningfully more concrete.

Why does the depth field use inches when length uses feet?

Because that is how slabs are specified in practice: a 10 by 10 foot pad at 4 inches deep. The tool converts internally, dividing inch values by 12 and centimetre values by 30.48, so you never have to enter a fractional foot.

Aussi connu sous le nom de

concrete calculatorhow much concrete do i needbags of concrete calculator

Calculateur de Volume de Béton et Sacs

Comment fonctionne le calcul

FAQ

Aussi connu sous le nom de

Outils similaires