Redmi K40S vs Xiaomi 15 Ultra
The Redmi K40S (2022) runs on the Qualcomm Snapdragon 870 5G, while the Xiaomi 15 Ultra (2025) runs on the Qualcomm Snapdragon 8 Elite. By overall MobileRank rating, the Xiaomi 15 Ultra leads — 85/100 vs 54/100 (a 31-point difference). Key differences: the Xiaomi 15 Ultra has the bigger battery (6000 mAh vs 4500); the main camera is 48 MP vs 50 MP; the Xiaomi 15 Ultra is faster in AnTuTu (3,030,376 vs 1,010,069); the Redmi K40S is noticeably lighter (195g vs 225g).
Redmi K40S
Xiaomi 15 Ultra
- Lighter: 195g vs 225g
- Better portability (65/100 vs 29/100)
- Higher AnTuTu: 3030376 vs 1010069
- Better Geekbench Single: 3050 vs 1298
- Better Geekbench Multi: 10200 vs 3520
- Bigger battery: 6000 vs 4500 mAh
- Faster charging: 90W vs 67W
- Better main camera: 50MP vs 48MP
- Higher performance (92/100 vs 61/100)
- Better camera (87/100 vs 36/100)
- Longer battery life (80/100 vs 42/100)
- Better display (90/100 vs 79/100)
Comparing the Redmi K40S vs the Xiaomi 15 Ultra, the Xiaomi 15 Ultra scores 31 points higher (85/100 vs 54/100). In the "performance" category, the Xiaomi 15 Ultra leads (92/100 vs 61/100). In the "camera" category, the Xiaomi 15 Ultra leads (87/100 vs 36/100). In the "battery" category, the Xiaomi 15 Ultra leads (80/100 vs 42/100). In the "performance" category, the Xiaomi 15 Ultra significantly outperforms the Redmi K40S (92/100 vs 61/100). In the "display" category, the Xiaomi 15 Ultra is a bit better (90/100 vs 79/100). In the "camera" category, the Xiaomi 15 Ultra significantly outperforms the Redmi K40S (87/100 vs 36/100). In the "battery" category, the Xiaomi 15 Ultra significantly outperforms the Redmi K40S (80/100 vs 42/100). In the "portability" category, the Redmi K40S significantly outperforms the Xiaomi 15 Ultra (65/100 vs 29/100).
| Specification | Redmi K40S | Xiaomi 15 Ultra | |
|---|---|---|---|
| Processor | Qualcomm Snapdragon 870 5G | Qualcomm Snapdragon 8 Elite | |
| AnTuTu | 1010069 | 3030376 | |
| Geekbench Single | 1298 | 3050 | |
| Geekbench Multi | 3520 | 10200 | |
| Display | 6.7" AMOLED | 6.7" LTPO AMOLED | |
| Resolution | 1080x2400 | 3200x1440 | |
| Refresh rate | 120 Hz | 120 Hz | |
| Battery | 4500 mAh | 6000 mAh | |
| Charging | 67W | 90W | |
| Wireless charging | 0W | 50W | |
| DXOMark (camera) | — | 159 | |
| Main camera | 48 MP | 50 MP | |
| Ultrawide | 8 MP | 50 MP | |
| Telephoto | 0 MP | 50 MP | |
| Front camera | 20 MP | 32 MP | |
| RAM | 6GB / 8GB / 12GB | 16GB | |
| Storage | 128GB / 256GB | 256GB / 512GB / 1TB | |
| OS | Android 12, MIUI 13 | Android 15 / HyperOS 2 | |
| Brightness (peak) | 1300 nits | 3200 nits | |
| NFC | yes | yes | |
| Protection | — | IP68 | |
| Dimensions | 163.2×76.0×7.7 mm | 161.3×75.3×9.4 mm | |
| Weight | 195 g | 225 g | |
| Price | — | $999 |
Redmi K40S
- Main: 48MP f/f/1.8
- Ultrawide: 8MP
- Front: 20MP
Xiaomi 15 Ultra
- Main: 50MP f/f/1.63
- Ultrawide: 50MP
- Telephoto: 50MP
- Front: 32MP
Redmi K40S
- 6.7" AMOLED
- Resolution: 1080x2400
- Refresh rate: 120 Hz
Xiaomi 15 Ultra
- 6.7" LTPO AMOLED
- Resolution: 3200x1440
- Refresh rate: 120 Hz
Redmi K40S
- 4500 mAh
- Wired: 67W
- No wireless charging
Xiaomi 15 Ultra
- 6000 mAh
- NanoReview test: web browsing 12:19 hrs, total 30:03 hrs
- Wired: 90W
- Wireless: 50W
We compared Redmi K40S and Xiaomi 15 Ultra, covering their specs and all relevant benchmarks.
Xiaomi 15 Ultra leads Redmi K40S by 66.7% in our overall performance rating.
Redmi K40S
Price unknownperformance
In the "performance" category, the Xiaomi 15 Ultra significantly outperforms the Redmi K40S (92/100 vs 61/100).
display
In the "display" category, the Xiaomi 15 Ultra is a bit better (90/100 vs 79/100).
camera
In the "camera" category, the Xiaomi 15 Ultra significantly outperforms the Redmi K40S (87/100 vs 36/100).
battery
In the "battery" category, the Xiaomi 15 Ultra significantly outperforms the Redmi K40S (80/100 vs 42/100).
portability
In the "portability" category, the Redmi K40S significantly outperforms the Xiaomi 15 Ultra (65/100 vs 29/100).
Which is better: the Redmi K40S or the Xiaomi 15 Ultra?
The Xiaomi 15 Ultra significantly outperforms the Redmi K40S by 31 points (85/100 vs 54/100).
What is the rating of the Redmi K40S and the Xiaomi 15 Ultra?
The Redmi K40S has a MobileRank rating of 54/100, the Xiaomi 15 Ultra — 85/100.
Which has the better camera: the Redmi K40S or the Xiaomi 15 Ultra?
The Xiaomi 15 Ultra leads on camera score (87/100 vs 36/100).
Which is more powerful: the Redmi K40S or the Xiaomi 15 Ultra?
The Xiaomi 15 Ultra leads on performance (92/100 vs 61/100).
Should you choose the Redmi K40S over the Xiaomi 15 Ultra?
The Redmi K40S is a better fit for active users. The Xiaomi 15 Ultra is a better fit for gamers and power users, mobile photography enthusiasts, those who care about battery life.