Same garden bed, two soil conditions - the difference is 30% more fertilizer. Enter the area, pick your plant type (lawn, vegetables, flowers, trees or universal) and soil fertility level. Get the dose per m2, total weight in kilograms, bag count and cost.
50 m2 garden - how much fertilizer do you need?
Same garden bed, two soil conditions - the difference is 30% more fertilizer. Enter the area, pick your plant type (lawn, vegetables, flowers, trees or universal) and soil fertility level. Get the dose per m2, total weight in kilograms, bag count and cost.
A 50 m2 lawn on medium-fertility soil needs about 70 g/m2 of NPK fertilizer - but the same area with poor sandy soil requires 30% more. Vegetables, flowers and trees each have different base doses ranging from 45 to 80 g/m2. Enter 50 below with your plant type and soil condition to get the precise weight in kilograms and the number of 5 kg or 10 kg bags to purchase.
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Fertilizer calculator - the right dose for every plant
Enter the area, select what you are growing and your soil condition. The calculator returns the fertilizer dose in g/m2, total weight, bag count and cost. A 100 m2 lawn on medium soil needs 7.0 kg of NPK fertilizer - but the same lawn on poor sandy soil needs 9.1 kg (+30%). That single variable changes your shopping list from 2 bags to 2 bags of 5 kg - same bag count, but almost no reserve left for the second application.
How to use the fertilizer calculator - step by step
- Area (m2) - total area to fertilize. Measure length x width of the bed, lawn or garden section.
- Plant type - lawn (70 g/m2 base), vegetables (60), flowers (45), trees/shrubs (80) or universal (40). Each has a different NPK emphasis.
- Soil fertility - low (+30% dose), medium (standard) or high (-30% dose). If unsure, select medium.
- Price (optional) - enter your local fertilizer price for a cost estimate.
- Read the results - dose per m2, total kg, bag count (5 kg and 10 kg), and cost.
Before and after - how soil fertility changes your dose
BEFORE - Poor sandy soil
Lawn 200 m2: 91 g/m2 = 18.2 kg
Vegetables 50 m2: 78 g/m2 = 3.9 kg
Flowers 30 m2: 59 g/m2 = 1.8 kg
Total: 23.9 kg | ~$96 at $4/kg
AFTER - Rich composted soil
Lawn 200 m2: 49 g/m2 = 9.8 kg
Vegetables 50 m2: 42 g/m2 = 2.1 kg
Flowers 30 m2: 32 g/m2 = 1.0 kg
Total: 12.9 kg | ~$52 at $4/kg
Dose reference table
| Plant type | Low soil | Medium soil | High soil | Key nutrient |
|---|---|---|---|---|
| Lawn | 91 g/m2 | 70 g/m2 | 49 g/m2 | Nitrogen (N) for green growth |
| Vegetables | 78 g/m2 | 60 g/m2 | 42 g/m2 | Potassium (K) for fruiting |
| Flowers | 59 g/m2 | 45 g/m2 | 32 g/m2 | Phosphorus (P) for blooming |
| Trees/shrubs | 104 g/m2 | 80 g/m2 | 56 g/m2 | Balanced NPK for roots |
| Universal | 52 g/m2 | 40 g/m2 | 28 g/m2 | NPK 15-15-15 balanced |
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Calculator verified by the LiczGrupa.pl team
Content, formulas and results have been reviewed for accuracy and relevance by our team of specialists.
Reviewed by: Patryk Matyjasik