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

https://fionafreshmaids.com/the-ultimate-guide-choosing-the-perfect-bedside-table-height-for-a-65-cm-mattress/

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