NPK.
The three numbers on a fertilizer label giving the percentage by weight of nitrogen (N), available phosphate (P₂O₅) and soluble potash (K₂O).
What it means for your plants
To convert to elements, multiply P₂O₅ by 0.436 and K₂O by 0.83. Compare ratios rather than size: foliage plants do well on nitrogen-leaning ratios around 3-1-2, and the working dilution, not the label number, sets what roots receive.
A 20-20-20 powder diluted as directed and a 2-2-2 liquid concentrate diluted as directed can deliver similar working solutions.
Put it into practice
What 10-10-10 or 3-1-2 really means: percent N, P₂O₅ and K₂O by weight, how to convert to elemental nutrients, and why ratio and dilution matter more than size.
NPK numbers explained: what a fertilizer label really tells you