The global demand for bottled king coconut water has led to a significant accumulation of empty king coconut husks in nut water export industries, posing challenges in managing and disposing of this agricultural waste. To address this issue, the production of king coconut husk ash (KCHA) has emerged as an eco-friendly solution. This product can be applied as a fertiliser, soil amendment, or after mixing with compost to enhance its nutrient value. This study aimed to determine the optimal cut size and moisture level for obtaining a high yield of KCHA with the maximum potassium content. The experiment involved drying full, half, quarter, and chip-sized husks in a dehydrator at 60°C for 0h, 2h, 4h, 8h, 12h, 24h, and 48h. The findings revealed that reducing the particle size of the husks accelerated the drying process. Ash produced with chips exhibited the most favourable characteristics, reaching the desired dryness in a relatively shorter time while yielding the highest KCHA content. Moreover, the results indicated that the optimal duration for dehydrating the husks to produce ash was 24h at 60 °C, resulting in 24 % of moisture content. This processing condition facilitated the efficient conversion of king coconut husks into potassium-rich ash. Implementing these findings into the production of KCHA as a nutrient-rich fertiliser or soil amendment offers a sustainable approach to improve agricultural practices while reducing the dependence on synthetic fertilisers and mitigating the environmental challenges associated with their accumulation.