Finding the perfect pair of running shoes is crucial—not only for comfort but also for performance and injury prevention. The Brooks Glycerin 20 is one of the brand’s most cushioned and supportive models, built for runners who crave softness and stability. But even the best shoe won’t serve you well if it doesn’t fit correctly. In this guide, we break down everything you need to know about Brooks Glycerin 20 sizing so you can get the ideal fit for your foot and running goals.
Why Sizing Matters in Running Shoes
Proper sizing impacts more than just comfort. Ill-fitting shoes can lead to blisters, black toenails, arch pain, and even knee or hip issues. The Brooks Glycerin 20 is designed to support neutral runners and those with mild underpronation, so nailing the fit means maximizing its advanced cushioning and DNA Loft v3 midsole technology.
Overview of the Brooks Glycerin 20 Fit
The Brooks Glycerin 20 tends to fit true to size for most runners. However, fit can vary depending on foot width, arch height, and intended use (daily training, long runs, or walking).
Key Fit Features:
- Roomy Toe Box: Allows natural toe splay
- Snug Midfoot: Offers secure lockdown without pressure
- Padded Heel Collar: Prevents slippage and provides a plush feel
- Available Widths: Narrow (2A), Medium (B for women, D for men), Wide (D for women, 2E for men), Extra Wide (4E for men)
Step-by-Step: How to Find Your Perfect Size
1. Measure Your Feet
- Stand on a piece of paper and trace your foot
- Measure from heel to longest toe (in centimeters or inches)
- Measure the widest part of your foot
- Always measure both feet (choose the size that accommodates the larger foot)
2. Check the Brooks Size Chart
Brooks provides sizing charts for both men and women. Use your foot length to find your size:
| US Women’s | Foot Length (inches) |
|---|---|
| 6 | 8.875 |
| 7 | 9.25 |
| 8 | 9.625 |
| 9 | 10 |
| 10 | 10.375 |
| US Men’s | Foot Length (inches) |
|---|---|
| 8 | 9.9375 |
| 9 | 10.25 |
| 10 | 10.5625 |
| 11 | 10.9375 |
| 12 | 11.25 |
Tip: Add a thumb’s width (~½ inch) to your measurement to allow for swelling during runs.
3. Choose the Right Width
- Narrow Foot: Try Narrow (2A) or stick with standard if unsure
- Standard Width: Most runners will be fine with B (women) or D (men)
- Wide Feet: Go for Wide (D women, 2E men) or Extra Wide (4E men)
Special Considerations
Orthotics or Insoles
If you use custom orthotics, consider sizing up by half a size or choosing a wider width to accommodate the additional volume.
Running Socks
Try on shoes with the same socks you plan to run in—especially if they’re thick or padded.
Different Glycerin Models
- Glycerin 20 StealthFit: Features a closer-to-foot, sock-like fit. Consider sizing up a half size if you prefer more toe room.
- Glycerin GTS 20: Offers added stability support (similar sizing to Glycerin 20, but with GuideRails tech)
Try Before You Fly
In-Store Fit Tip:
- Walk and jog in the store to get a feel for heel slippage, toe pressure, and arch support
- Test both shoes—even if one foot feels great, the other may differ
Online Buying Advice:
- Buy from retailers with good return policies (Brooks offers a 90-day Run Happy guarantee)
- Order two sizes if unsure and return the one that doesn’t fit
Final Fit Checklist
Ask yourself these questions once you have them on:
- Can you wiggle your toes freely?
- Does your heel feel locked in with no slipping?
- Do your arches feel supported but not pressured?
- Do your feet feel secure but not cramped?
If you answered “yes” to all, you’ve likely found your perfect Brooks Glycerin 20 size.
Conclusion
The Brooks Glycerin 20 delivers exceptional comfort, especially for long runs and daily training, but only if you choose the right size. Whether you’re a beginner runner or training for a marathon, use this size guide to ensure a fit that supports your stride from mile one to the finish line. Happy running!
