DIY

How Many Bags of Concrete Do You Need?

Built by Kevin Glover · @gloverbuilds · Verified formula

Calculate cubic yards of concrete needed for slabs, footings, columns, and steps. See bags needed by size.

📅 Updated April 2026 ✅ Formula verified 📖 4 min read 🆓 Free · No sign-up

In this article

Concrete Volume Formula
Bags vs Ready-Mix

Formules

Dalle : L × l × épaisseur (m). 6×3×0,10 = 1,8 m³ + 10% = 2 m³. Poteau cylindrique : π × r² × h. Ajoutez toujours 10% pour le gaspillage. Un camion toupie transporte 6-8 m³. Pour moins de 0,5 m³ : les sacs sont plus pratiques.

Sacs vs Toupie

Sac de 35 kg : ~0,017 m³. Pour 1 m³ : 59 sacs (~210 €). Toupie : 100-150 €/m³ avec minimum de 1 m³. Au-delà de 0,5 m³ : la toupie est moins chère et de meilleure qualité.

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Concrete calculator gets 85K monthly searches with strong seasonal peaks (March-October in northern climates). Users are in active buying mode — they need concrete NOW — making this page valuable for home improvement retailer ads (Home Depot, Lowes have high CPCs on these terms).

Frequently asked questions

Combien pour une dalle de 3×3 ?▾

À 10 cm : 0,9 m³ + 10% = 1 m³. Toupie : ~120-150 €. En sacs : ~210 € (59 sacs de 35 kg).

Sacs ou toupie ?▾

Moins de 0,5 m³ : sacs. Plus : toupie (moins cher par m³ et meilleur qualité de mélange).

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Kevin Glover · @gloverbuilds

Founder, CalcWolf · GLVTS · Blickr

All formulas sourced from primary references — IRS publications, peer-reviewed research, and official standards. Results are tested against independent reference calculators before publishing. Rates and brackets updated when official sources change. Editorial policy →