How Much Bedding Does a Pig Need?

Bedding depth for pigs is genuinely less standardised than space requirements — there's no legal minimum or welfare-certification figure the way there is for pen size. What follows is a sensible starting point to plan around, not a fixed rule.

A starting depth of around 12.5cm (4–6 inches)

Iowa State University's extension guidance on bedding management for niche pork production puts a practical starting depth at roughly 12.5cm, or 4–6 inches. That's the figure this site's bedding calculator uses to turn your pen's floor area into an estimated volume of bedding to start with.

What our own bedding calculator doesn't account for

In the interest of the same sourcing discipline we hold every figure on this site to: the bedding calculator lets you pick a material (straw, wood shavings, hemp bedding, or other), but that choice only changes the label on the result, not the depth figure itself. Straw, wood shavings and hemp bedding compact and insulate differently in practice, but no source we found publishes a material-specific starting depth for pigs specifically — so rather than invent per-material numbers, the calculator uses one species-level planning depth and says so plainly here rather than implying more precision than the data actually supports.

Deep bedding (deep litter) vs. regularly mucked-out systems

The 12.5cm figure is a starting depth, not a constant. In a regularly mucked-out system, soiled bedding is removed and topped back up to roughly that depth on an ongoing basis. In a deep-litter system, fresh material is added on top over time instead of being fully replaced, and the total depth builds up well beyond the starting figure as the season goes on — the calculator estimates your first fill, not ongoing top-ups either way.

Bedding isn't only comfort: rooting material is a legal requirement in England

Schedule 8 of the Welfare of Farmed Animals (England) Regulations 2007, as quoted in Defra's guidance on caring for pigs, requires that all pigs have permanent access to a sufficient quantity of material such as straw, hay, wood, sawdust, mushroom compost or peat. The point is enrichment as well as warmth: pigs need something to root in and explore. It's one reason a bare, hard floor isn't an acceptable saving, and why a bedding budget is a welfare cost rather than an optional extra. Whether Schedule 8 binds a particular pet pig depends on how it is kept, but it is the clearest statement of what the law treats as acceptable.

Bedding for farrowing is different

If you are keeping a sow that's about to farrow, The Pig Site advises using shorter or chopped straw for bedding, because newborn piglets are less likely to get caught up in it or bury themselves, which makes them harder for the sow to see. Our guide to pig gestation and farrowing covers when to prepare the farrowing area.

Working out how much to buy

Enter your pen's floor area — from the pig pen size calculator if you haven't worked that out yet — into the bedding calculator along with your bag or bale size, and it converts the starting depth into a number of bags to buy.

Common questions

Does the type of bedding material change how much I need?

In practice, yes — materials compact and insulate differently. Our own bedding calculator is honest about not modelling this: it uses one starting depth per species regardless of material, since no source we found publishes a material-specific depth for pigs specifically. Treat the depth figure as a starting point and adjust based on how your chosen material behaves once it's down.

How often does pig bedding need replacing?

It depends on your system. A regularly mucked-out pen needs soiled bedding removed and topped up frequently — often every few days for the areas pigs dung in. A deep-litter system is managed differently: fresh material is added on top over time rather than fully replaced, and depth builds up well beyond the starting figure.

Is 12.5cm enough bedding depth for outdoor pigs in winter?

12.5cm (about 4-6 inches) is a general starting depth, not a cold-weather minimum. Outdoor pigs in colder conditions typically need noticeably more depth for insulation and a dry lying area — treat the figure here as a baseline to build up from, not a year-round constant.