For the best comfort, your nightstand should sit level with the top of your...

https://lilyluxemaids.com/the-golden-ratio-of-bedside-comfort-matching-your-mattress-to-a-60-63-cm-nightstand/

For the best comfort, your nightstand should sit level with the top of your mattress or just 5-10 cm below it. Reaching for a glass of water shouldn't feel like a workout. Most standard UK beds pair perfectly with tables between 55-70 cm high