How many gel packs do you need? Complete calculation formula
Short answer: for a 24-hour shipment at 15–20 °C, allow for approximately 200 grams of gel packs per kilo of product (formula: product weight × 0.2). For 48-hour transport in summer, this rises to around 500 grams per kilo. Also adjust for transport time, outside temperature and the type of box — the exact factors are listed below.
Too few coolants means a risk of spoilage, while too many means unnecessary shipping costs and weight. Use this calculation formula to determine the right quantity.
The basic formula
For a typical 24-hour shipment at normal outside temperatures (15-20°C):
Gel packs required (grams) = Product weight (grams) × 0.2
Example: 5 kg of meat × 0.2 = 1 kg of gel packs (e.g. 2 or 3 packs of 400g)
Adjustment factors
Transport time
- 12 hours: multiply by 0.5
- 24 hours: standard (1.0)
- 48 hours: multiply by 1.8
- 72 hours: multiply by 2.5
Outside temperature
- Winter (0-10°C): multiply by 0.7
- Spring/autumn (15-20°C): standard (1.0)
- Summer (20-25°C): multiply by 1.4
- Hot summer (25+°C): multiply by 1.8
Box insulation
- Polystyrene Box 30mm wall: standard (1.0)
- Polystyrene Box 50mm wall: multiply by 0.7
- Honeycomb box: multiply by 1.2
- Standard cardboard box: multiply by 2.5
Example calculation
You are shipping 3 kg of fish, 48-hour transport, summer (24°C), Polystyrene Box with 30mm wall:
3000 g × 0.2 = 600 g base
600 × 1.8 (48 hours) = 1080 g
1080 × 1.4 (summer) = 1512 g
Result: approximately 1.5 kg of gel packs required. For example, 4 packs of 400g.
Pro tips
- Distribute the gel packs around the product — not just on one side
- Place them on top of the product (cold air sinks) for fresh products
- Always use absorbent pads to catch meltwater
- Pre-freeze the gel packs for at least 24 hours
- Test your packaging with a data logger if in doubt
Table: quick reference
| Product weight | 24h (standard) | 48h (summer) |
|---|---|---|
| 1 kg | 200 g | 500 g |
| 2 kg | 400 g | 1000 g |
| 5 kg | 1000 g | 2500 g |
| 10 kg | 2000 g | 5000 g |
Still unsure?
For specific calculations for your use case, please contact our sales support team. We have experience with thousands of customer situations and are happy to help.
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