Best Baby Sleep Sacks 2026: TOG Ratings and Top Picks
A sleep sack (sleeping bag) replaces loose blankets in the crib, which are a SIDS risk factor. All European health authorities recommend sleep sacks over blankets for babies under 12 months. The main decision is choosing the right TOG rating for your room temperature.
TOG Ratings Explained
TOG (Thermal Overall Grade) measures thermal resistance, how well a fabric insulates. Higher TOG = warmer. Sleep sacks typically come in 0.5, 1.0, and 2.5 TOG. The right TOG depends on your room temperature, not the outdoor temperature.
Matching TOG to Room Temperature
| Room temperature | TOG to use | What baby wears underneath |
|---|---|---|
| Below 16°C | 2.5 TOG + consider extra layer under | Long-sleeve vest + babygrow |
| 16–18°C | 2.5 TOG | Long-sleeve babygrow |
| 18–20°C | 1.0 TOG | Long-sleeve babygrow |
| 20–22°C | 1.0 TOG | Short-sleeve vest |
| 22–24°C | 0.5 TOG | Short-sleeve vest or nappy only |
| Above 24°C | 0.5 TOG or just nappy | Nappy only in very warm rooms |
Check room temperature, not how you feel
Parents are often dressed and moving around; babies are stationary. What feels comfortable to you may be too warm for a baby in a sleep sack. Use a room thermometer to check the actual temperature where baby sleeps, and use that, not your intuition, to choose the TOG.
Our 2026 Sleep Sack Rankings
| Sleep sack | Score | TOG options | Age range | Buy |
|---|---|---|---|---|
| Gro Company Grobag 🏆 | 4.7 | 0.5, 1.0, 2.5 | 0–6yr | |
| Love to Dream Transition Bag | 4.6 | 0.2, 1.0 | 3–9 months | |
| HALO SleepSack | 4.4 | 0.5, 1.5, 3.5 | Birth–5yr | |
| IKEA GULSPARV 💰 | 4.1 | TOG varies by product | 0–12 months | 🇩🇪 IKEA |
Transitioning from Swaddle to Sleep Sack
The transition from swaddle to sleep sack is one of the trickier sleep transitions in the first year. The best approach:
- Triggered by rolling: Stop swaddling the moment baby shows any rolling sign, immediately switch to a sleep sack
- Gradual approach: Use the Love to Dream Swaddle UP Transition Bag, start with both wings zipped on (swaddled), then zip one wing off, then both. The same product throughout the transition reduces disruption
- Cold turkey: Some babies transition immediately with minimal disruption, particularly those who were already trying to break out of the swaddle
See our full guide: When to Stop Swaddling.