Concrete Bag Calculator — m, kg bags, cost comparison
How to use this calculator
Choose how to enter your volume: type in m³ or liters directly, or enter length × width × depth dimensions. The calculator shows a side-by-side comparison of all common metric bag sizes so you can pick the most economical option.
Direct volume — enter m³ or liters if you already know the volume.
Dimensions — enter L × W in meters/cm, depth in cm for automatic calculation.
Waste — always add 10–15% for spillage and over-excavation.
| Bag Size | Yield | Bags | Weight | Cost |
|---|---|---|---|---|
| 20 kg | 0.010 m³ | — | — | — |
| 25 kg | 0.012 m³ | — | — | — |
| 40 kg | 0.019 m³ | — | — | — |
| 50 kg | 0.024 m³ | — | — | — |
Saved Calculations
| Time | Volume | 20 kg | 25 kg | 50 kg | Best Cost |
|---|
How Many Bags of Concrete Do I Need? (Metric)
This concrete bag calculator helps you determine the exact number of premixed concrete bags for any project. Enter your volume directly in m³ or liters, or input length × width × depth dimensions. The calculator compares all common metric bag sizes (20, 25, 40, and 50 kg) side by side.
Bag Yield Reference
Approximate yield per bag of premixed concrete:
20 kg = 0.010 m³ (10 L) · 25 kg = 0.012 m³ (12 L) · 40 kg = 0.019 m³ (19 L) · 50 kg = 0.024 m³ (24 L)
Based on standard premixed dry concrete with a yield density of approximately 2,100 kg/m³ when mixed.
Formula
Volume: L (m) × W (m) × D (m) = m³. Multiply by 1,000 for liters.
Bags: ⌈volume (m³) / yield per bag⌉ × (1 + waste%)
FAQ
Which bag size is best? 25 kg bags are easiest to handle for DIY projects. 50 kg bags offer better value for larger pours but require more strength to carry.
How many 25 kg bags per m³? Approximately 84 bags (1 m³ / 0.012 m³ per bag ≈ 84 bags).
