The Adidas Women’s Ultraboost 21 in Black/Grey is a high-performance neutral road running shoe that blends plush cushioning, responsive energy return and everyday versatility. Ideal for women who want a premium daily trainer that feels just as good on a long run as it does for gym sessions and all-day wear.
Key Features
- Responsive Boost cushioning: Full-length Boost midsole delivers soft landings with powerful energy return on every stride.
- Supportive Primeknit+ upper: Wraps the foot in a breathable, sock-like fit that adapts to your natural movement.
- Linear Energy Push (LEP) system: Adds forefoot stiffness to create a more propulsive, snappy toe-off.
- Continental™ Rubber outsole: High-traction rubber compound for confident grip on wet and dry roads.
- Secure heel fit: Sculpted heel and molded counter help lock the rearfoot in place for stable transitions.
- Stylish black/grey colourway: Versatile athleisure look that pairs easily with running gear or everyday outfits.
Specifications
- Category: Neutral women’s road running shoe
- Best for: Daily training, easy runs, steady mileage and walking
- Midsole: Full-length Boost cushioning
- Upper: Primeknit+ textile
- Outsole: Continental™ Rubber
- Drop: 10 mm (heel height approx. 30.5 mm / forefoot approx. 20.5 mm)
- Surface: Road and paved paths
- Fit: Snug, sock-like upper with secure heel hold
Ideal Use
This Ultraboost 21 is perfect if you:
- Want a cushioned women’s runner for daily kilometres on the road.
- Like a soft, bouncy ride that still feels stable underfoot.
- Need one shoe that can handle running, gym sessions and casual wear.
- Prefer a premium, stylish black/grey sneaker you can wear all day.
Care
- Brush off loose dirt after each wear, especially around the outsole and knit upper.
- Spot clean with mild soap and cold water; avoid harsh chemicals or bleach.
- Air dry at room temperature away from direct heat or sunlight.
- Remove insoles after heavy use to help them dry fully and reduce odour.
- Rotate with another pair of shoes between runs to prolong cushioning life.
Adidas Shoe Size Chart
Get the perfect fit for your Adidas shoes with AdventureCo’s complete size chart. Compare men’s and women’s US, UK, EU sizes and foot length in centimeters (cm). Easy 365-day returns if it's not right.
Size Conversion Table
| US (Men) | US (Women) | CM | UK | EU |
|---|---|---|---|---|
| 4 | 5 | 22.1 | 3.5 | 36 |
| 4.5 | 5.5 | 22.5 | 4 | 36 2/3 |
| 5 | 6 | 22.9 | 4.5 | 37 1/3 |
| 5.5 | 6.5 | 23.3 | 5 | 38 |
| 6 | 7 | 23.8 | 5.5 | 38 2/3 |
| 15 | 16 | 31.8 | 14.5 | 50 2/3 |
How to Measure Your Foot
- Place your heel against a wall, mark the tip of your longest toe, and measure from the wall—in centimeters.
- Refer to the “CM” column to find your corresponding size.
- Measure at the end of the day when your feet are typically largest.
Sizing Tips & Return Policy
- Adidas sizes are generally true to fit, but can vary by model—some narrower or wider than others.
- For a snug fit, consider going down half a size; for a roomier fit, go up half a size.
- All unused items can be returned or exchanged within 365 days—no hassle, flexible returns policy.
The Adidas Women’s Ultraboost 21 in Black/Grey is a high-performance neutral road running shoe that blends plush cushioning, responsive energy return and everyday versatility. Ideal for women who want a premium daily trainer that feels just as good on a long run as it does for gym sessions and all-day wear.
Key Features
- Responsive Boost cushioning: Full-length Boost midsole delivers soft landings with powerful energy return on every stride.
- Supportive Primeknit+ upper: Wraps the foot in a breathable, sock-like fit that adapts to your natural movement.
- Linear Energy Push (LEP) system: Adds forefoot stiffness to create a more propulsive, snappy toe-off.
- Continental™ Rubber outsole: High-traction rubber compound for confident grip on wet and dry roads.
- Secure heel fit: Sculpted heel and molded counter help lock the rearfoot in place for stable transitions.
- Stylish black/grey colourway: Versatile athleisure look that pairs easily with running gear or everyday outfits.
Specifications
- Category: Neutral women’s road running shoe
- Best for: Daily training, easy runs, steady mileage and walking
- Midsole: Full-length Boost cushioning
- Upper: Primeknit+ textile
- Outsole: Continental™ Rubber
- Drop: 10 mm (heel height approx. 30.5 mm / forefoot approx. 20.5 mm)
- Surface: Road and paved paths
- Fit: Snug, sock-like upper with secure heel hold
Ideal Use
This Ultraboost 21 is perfect if you:
- Want a cushioned women’s runner for daily kilometres on the road.
- Like a soft, bouncy ride that still feels stable underfoot.
- Need one shoe that can handle running, gym sessions and casual wear.
- Prefer a premium, stylish black/grey sneaker you can wear all day.
Care
- Brush off loose dirt after each wear, especially around the outsole and knit upper.
- Spot clean with mild soap and cold water; avoid harsh chemicals or bleach.
- Air dry at room temperature away from direct heat or sunlight.
- Remove insoles after heavy use to help them dry fully and reduce odour.
- Rotate with another pair of shoes between runs to prolong cushioning life.
Adidas Shoe Size Chart
Get the perfect fit for your Adidas shoes with AdventureCo’s complete size chart. Compare men’s and women’s US, UK, EU sizes and foot length in centimeters (cm). Easy 365-day returns if it's not right.
Size Conversion Table
| US (Men) | US (Women) | CM | UK | EU |
|---|---|---|---|---|
| 4 | 5 | 22.1 | 3.5 | 36 |
| 4.5 | 5.5 | 22.5 | 4 | 36 2/3 |
| 5 | 6 | 22.9 | 4.5 | 37 1/3 |
| 5.5 | 6.5 | 23.3 | 5 | 38 |
| 6 | 7 | 23.8 | 5.5 | 38 2/3 |
| 15 | 16 | 31.8 | 14.5 | 50 2/3 |
How to Measure Your Foot
- Place your heel against a wall, mark the tip of your longest toe, and measure from the wall—in centimeters.
- Refer to the “CM” column to find your corresponding size.
- Measure at the end of the day when your feet are typically largest.
Sizing Tips & Return Policy
- Adidas sizes are generally true to fit, but can vary by model—some narrower or wider than others.
- For a snug fit, consider going down half a size; for a roomier fit, go up half a size.
- All unused items can be returned or exchanged within 365 days—no hassle, flexible returns policy.
10,000+ Reasons to Give Us a Try
At Adventureco, we stand behind every product we sell. That’s why you’re covered by our 365-Day Return Policy — with free returns within Australia.
Not the right fit? Changed your mind? No worries. Return your gear in unused condition within 365 days for a full refund or store credit — no fuss, no pressure.
Trusted for 9+ years and over 10,000 orders delivered. Shop with confidence, the adventure is guaranteed.