Ready-Mix vs Bags Calculator
Compares the true cost of bagged concrete against a ready-mix delivery for the same volume, including the minimum load and any delivery or short-load fee. Cost is only half the answer — the weight figure is the other half.
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
The formula
bags = count × price · ready-mix = max(volume, minimum) × price + fees
The comparison turns on the supplier minimum. Below it you pay for concrete you do not receive, which is what makes small pours look expensive on paper.
What to watch out for
Three things the sticker price hides:
- The minimum load. Need 0.6 m³ from a supplier with a 1 m³ minimum and you pay for 1 m³. That single fact decides most small pours.
- The short-load fee. Common below about 3 m³ and often £30–60, which can exceed the concrete cost on a small order.
- The labour is not free. A cubic metre is 80 bags: two tonnes to move, open and mix, and it all has to go in before the first batch starts setting. Bags being cheaper on paper does not make them cheaper in practice.
Frequently Asked Questions
Is ready-mix cheaper than bags?
Per cubic metre, almost always — often by half. The exception is small volumes, where the supplier minimum and short-load fee mean you pay for concrete you never receive.
What is the break-even point?
Typically around 0.5–1 m³, depending on your bag price and the supplier minimum. This calculator finds the crossover for your actual numbers rather than a rule of thumb.
What is a short-load fee?
A surcharge for deliveries below a full load — commonly under 3 m³. It covers the truck making a trip that is not worth its capacity, and it can easily double the cost of a small pour.
Is a cheaper bag total worth the work?
Below about 0.5 m³, usually yes. Above 1 m³, rarely — mixing a tonne-plus by hand while keeping a continuous pour is genuinely difficult, and a cold joint costs more than the saving.