Adidas Women’s Ultraboost 21 – Core Black/Core Grey
The Adidas Ultraboost 21 in Core Black/Core Grey is a high-performance women's shoe designed for running, training, and everyday wear. Combining iconic Ultraboost style with cutting-edge comfort and performance tech, this shoe delivers the energy and support you need from your first step to your last.
Responsive Energy. All-Day Style.
With more BOOST cushioning than ever before, the Ultraboost 21 delivers explosive energy return with every stride. The sock-like Primeknit upper wraps your foot for a supportive, flexible fit, while the Continental™ Rubber outsole keeps you grounded on any surface.
Key Features:
- BOOST midsole: Maximum energy return and cushioning
- Primeknit+ upper: Adaptive and breathable sock-like fit
- LEP system: Linear Energy Push torsion system for stability and propulsion
- Continental™ Rubber outsole: Exceptional grip in all conditions
- Sustainable design: Made in part with recycled materials
Perfect For:
- Road running and treadmill workouts
- Gym sessions and cross-training
- Comfortable everyday wear
Specifications:
- Colour: Core Black / Core Grey
- Midsole: Full-length BOOST cushioning
- Upper: Primeknit+ textile
- Outsole: Continental™ Rubber
- Drop: Approx. 10mm
- Fit: Regular with sock-like comfort
Care Instructions:
Clean with a soft brush and mild soap. Air dry away from direct sunlight. Do not machine wash.
Built to Perform. Styled to Move.
The Adidas Women’s Ultraboost 21 delivers powerful energy, day-long comfort, and a sleek look—ideal for runners, gym-goers, and anyone always on the move.
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.
Adidas Women’s Ultraboost 21 – Core Black/Core Grey
The Adidas Ultraboost 21 in Core Black/Core Grey is a high-performance women's shoe designed for running, training, and everyday wear. Combining iconic Ultraboost style with cutting-edge comfort and performance tech, this shoe delivers the energy and support you need from your first step to your last.
Responsive Energy. All-Day Style.
With more BOOST cushioning than ever before, the Ultraboost 21 delivers explosive energy return with every stride. The sock-like Primeknit upper wraps your foot for a supportive, flexible fit, while the Continental™ Rubber outsole keeps you grounded on any surface.
Key Features:
- BOOST midsole: Maximum energy return and cushioning
- Primeknit+ upper: Adaptive and breathable sock-like fit
- LEP system: Linear Energy Push torsion system for stability and propulsion
- Continental™ Rubber outsole: Exceptional grip in all conditions
- Sustainable design: Made in part with recycled materials
Perfect For:
- Road running and treadmill workouts
- Gym sessions and cross-training
- Comfortable everyday wear
Specifications:
- Colour: Core Black / Core Grey
- Midsole: Full-length BOOST cushioning
- Upper: Primeknit+ textile
- Outsole: Continental™ Rubber
- Drop: Approx. 10mm
- Fit: Regular with sock-like comfort
Care Instructions:
Clean with a soft brush and mild soap. Air dry away from direct sunlight. Do not machine wash.
Built to Perform. Styled to Move.
The Adidas Women’s Ultraboost 21 delivers powerful energy, day-long comfort, and a sleek look—ideal for runners, gym-goers, and anyone always on the move.
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.
