How Much Ice Do You Need for an Ice Bath?
Ice baths and cold plunges have become part of many training and wellness routines. The question everyone asks first is simple: how much ice does it take? Here is a practical guide.
The short answer
About 30–40 kg of ice (roughly three 12 kg bags) brings a 300-litre tub of cold tap water down by around 10°C. A small barrel or 150-litre tub needs about half that. If your tap water is warm in summer, or you want the bath colder, add more.
Why it takes so much ice
Melting ice absorbs a lot of heat, but water holds a lot of heat too. Every kilo of ice melting in the bath cools roughly 8 litres of water by about 10°C. That is why a bag or two from the supermarket rarely gets a full tub cold.
What temperature do people aim for?
Most people use water between about 10°C and 15°C, and experienced users sometimes go colder. Beginners usually start at the warmer end and stay in for only a minute or two, building up gradually. A cheap pool thermometer makes it easy to check.
Quick quantity table
| Tub size | Ice for about a 10°C drop |
|---|---|
| 150 litres | 15–20 kg (1–2 bags) |
| 300 litres | 30–40 kg (3 bags) |
| 500 litres | 50–65 kg (4–5 bags) |
Making the ice last
- Fill the tub with the coldest tap water first, then add ice just before you get in.
- Use cube ice rather than crushed; it melts more slowly.
- Keep a lid on the tub and keep it out of direct sun.
- Store spare bags in a freezer or a cool box until needed.
Safety
Cold water immersion is not suitable for everyone. If you have a heart condition, high blood pressure or another health concern, or are pregnant, speak to a doctor first. Never take an ice bath alone, and get out straight away if you feel dizzy or unwell. Never use dry ice in an ice bath.
Running sessions for a gym or club? See ice for ice baths and sports recovery.
Ordering ice from Nice Ice
- £10 per 12 kg bag: cube ice, crushed ice or 6 × 2 kg bags.
- Free delivery across London from 5 bags.
- Order by 5pm for next-day delivery, Monday to Saturday, morning or afternoon slot.
- Regular orders? Open a trade account.
Frequently asked questions
How many bags of ice for an ice bath? Around three 12 kg bags for a 300-litre tub of cold tap water, which lowers it by about 10°C.
What temperature should an ice bath be? Most people use water between about 10°C and 15°C. Beginners usually start at the warmer end with short sessions.
Is cube or crushed ice better for an ice bath? Cube ice. It melts more slowly in water, so the bath stays cold for longer.
Can I use dry ice in an ice bath? No. Dry ice can cause severe cold burns and releases carbon dioxide gas. Never put it in a bath.
