Top 10 · Compare
Compare Best Long Underwear head to head
Pick any two picks from this list and see specs, current price, pros, cons and reader ratings side by side.
Back to the full Top 10


#4 on this list
Classic Thermal Merino 250
Smartwool
The best-cut 250-weight in the US, with a body-mapped fit that never rides up.
- Price
- Check current price
- Reader rating
- No reader votes yet
- How we assessed it
- Specification researched

#5 on this list
230 Competition
Ortovox
Austrian Merino with mesh panels where you overheat. Best for hard uphill in cold air.
- Price
- Check current price
- Reader rating
- No reader votes yet
- How we assessed it
- Specification researched
Specs side by side
| Spec | Classic Thermal Merino 250 | 230 Competition |
|---|---|---|
| Maker | Smartwool | — |
| Material | 100% Merino Wool | 80% Merino Wool, 20% Polyamide |
| Fabric Weight | 250 g/m² | — |
| Fit | Slim, body-mapped | Athletic, form-fitting |
| Best For | Cold weather layering, skiing, hiking | — |
| Weight | — | 230 g/m² (main fabric) |
| Construction | — | Body-mapped knit |
| Odor Resistance | — | High |
| Origin | — | Austria (wool) |
What our reviewers liked and didn't
Classic Thermal Merino 250
- Excellent thermal regulation and breathability across varied activity levels
- Superior odor resistance for multi-day wear
- Thoughtful, body-mapped fit that doesn't ride up or restrict movement
- Soft next-to-skin feel, no itch
- Good balance of warmth for its moderate weight
- Higher price point compared to synthetic options
- Slower drying time than pure synthetics when soaked
230 Competition
- Exceptional temperature regulation via body-mapping
- Highly breathable, prevents overheating during exertion
- Excellent odor resistance, suitable for multi-day use
- Comfortable, non-chafing seamless construction
- Good balance of warmth, durability, and stretch
- Premium price point may be prohibitive for some
- Requires careful washing to maintain integrity
- Snug fit may not appeal to all users
Prices change constantly — the figure shown is the last verified catalog price, and the buy buttons always go to the current listing.


