Concrete vs Cement: What's the Difference?
The two words get used interchangeably, but they're not the same thing — and the difference is exactly what trips people up at the hardware store. Cement is the fine grey powder that acts as the binder. Concrete is the finished, pourable material made by combining cement with sand, gravel (coarse aggregate) and water. Put simply: cement is an ingredient; concrete is the recipe.
How the recipe works
When water is added, the cement forms a paste that coats every grain of sand and piece of gravel, then hardens through hydration, locking the whole mass into a solid. The sand fills the gaps between the gravel; the gravel gives the concrete its bulk and strength; the cement paste glues it all together. A typical mix is roughly 1 part cement : 2 parts sand : 3 parts aggregate, plus enough water to react and make it workable.
Cement, concrete, mortar and grout
| Material | What's in it | Used for |
|---|---|---|
| Cement | The binder powder alone | An ingredient, not used by itself |
| Concrete | Cement + sand + gravel + water | Slabs, footings, driveways, posts |
| Mortar | Cement + sand + water (no gravel) | Laying brick and block |
| Grout | Flowable cement + fine aggregate | Filling block cores, gaps |
What this means when you're buying
A bag labelled "concrete mix" already contains the cement, sand and gravel — you just add water. A bag of "Portland cement" is the powder on its own, and you supply your own sand and aggregate to make concrete or mortar. For nearly all slabs, footings and posts, a pre-blended concrete mix is the simplest and safest choice; buying straight cement only makes sense if you're batching a custom mix in volume.
A note on strength
Because cement is the active binder, more cement generally means stronger concrete — but the bigger lever is actually the water-to-cement ratio, not just how much cement you use. To work out the cement, sand and aggregate quantities for a custom batch from a wet volume, use the mix ratio calculator; for ready-blended bags, the bag calculator tells you how many you need.