How many bags of Postcrete do I need?
Enter the number of fence posts and we'll work out the bags of fast-setting post mix and the cost — with the calculation shown. Most posts take one to two bags.
2 bags per post.
| Postcrete (20kg, fence posts) | 20 × 20 kg bag | £140 |
- 1Number of posts: 10
- 2Usage rate: 2 bags per post
- 3Material needed: 10 × 2 = 20 bag
- 4Quantity: 20 × 20 kg bag @ £7 each
- Material cost only — labour is estimated separately in the schedule.
- Indicative trade-counter price; confirm with a current supplier quote.
How to work out Postcrete quantities
- 1Count the posts
For a fence run, count the posts — typically one every ~1.8 m (one per panel), plus the end and corner posts.
- 21–2 bags per post
A standard timber fence post in a normal hole takes about one to two bags of fast-setting post mix. Bigger posts or gate posts take more.
- 3Bigger holes need more
Gate posts, tall fences and exposed sites need deeper, wider holes and more mix — allow extra for those.
- 4Keep a couple spare
It sets fast and you can't half-use a bag easily, so round up and keep one or two spare for the last, awkward post.
Fencing is one of the most common outdoor jobs, and the number people most often get wrong is the post mix — buy too little and you're stuck mid-run waiting on the merchant. Counting posts and allowing one to two bags each (more for gates) is the quick way to order the right amount.
Postcrete per post (indicative)
| Post type | Bags per post | Notes |
|---|---|---|
| Standard fence post | 1–2 | ~600 mm deep hole |
| Tall / exposed fence | 2–3 | Deeper, wider hole |
| Gate post | 2–4 | Larger post, more load |
| Concrete post | 2+ | Heavier, bigger hole |
Fast-setting post mix (e.g. Postcrete) goes off in minutes — mix in the hole per the pack. Indicative — confirm with quotes.
Frequently asked questions
How many bags of Postcrete per fence post?+
About one to two bags for a standard timber fence post in a normal-sized hole. Gate posts, tall fences and exposed positions need deeper holes and two to four bags.
How deep should a fence post hole be?+
As a rule of thumb, bury about a quarter to a third of the post — so a hole around 600 mm deep for a typical fence, deeper for tall or exposed fences and gate posts.
How much Postcrete do I need for a whole fence?+
Count the posts (roughly one per 1.8 m panel plus ends and corners) and multiply by one to two bags each. The calculator totals the bags and cost.
Related tools & guides
Want to know how these figures are calculated? See our cost methodology.
Cost figures shown are indicative estimates, not quotations. You are responsible for verifying all costs (obtain contractor quotes) and any figures submitted to a lender. ScopeWise is a documentation tool, not financial, tax, structural or planning advice. HMO compliance prompts are guidance only — confirm requirements with your local council, as standards and licensing vary by authority.