Turn any label into real nutrient amounts. Blend sources, track NPK balance, and avoid overfeeding. Plan smarter schedules for healthier soil and plants ahead.
| Area | Product | N–P₂O₅–K₂O | Amount |
|---|---|---|---|
| 20 m² | Urea | 46–0–0 | 200 g |
| 20 m² | Monoammonium phosphate | 11–52–0 | 150 g |
| 20 m² | Potassium sulfate | 0–0–50 | 120 g |
Fertilizer labels show N–P₂O₅–K₂O percentages, but plants respond to actual nutrient grams delivered. Measuring contributions avoids “stacking” nutrients from multiple inputs, limits salt burn, and improves consistency between feedings. Normalizing by m², hectare, or 1000 ft² makes beds, containers, and lawns comparable, even when you change products or application frequency.
Nitrogen supports leaf growth and chlorophyll, so too much often creates weak, watery tissue and higher pest pressure. Phosphate is reported as P₂O₅; to compare with soil tests that use elemental P, convert using P = P₂O₅ × 0.4364. Potash is reported as K₂O; convert to elemental K with K = K₂O × 0.8301 when balancing to lab targets.
Garden programs commonly blend quick sources, slow organics, and micronutrient mixes. This calculator sums each row’s nutrient mass, then aggregates totals across all products, so you can see the true NPK load. If one nutrient runs high, reduce that product first and replace missing nutrients with a more focused source. Splitting into smaller doses improves uptake and reduces leaching after heavy irrigation.
Begin with a nutrient target and work backward: Fertilizer(g) = Target nutrient(g) ÷ (Percent ÷ 100). Example: applying 10 g N over 20 m² using 46% N requires 21.7 g fertilizer total, or 1.09 g/m². The tool then reports equivalent rates in kg/ha or lb/1000 ft² for easy comparison with extension guides and label instructions. Recheck totals whenever area or row count changes.
Soil reports often use elemental P and K, while product labels use oxides. Showing both forms bridges that mismatch and supports better decisions. Combine results with soil organic matter, crop removal estimates, and irrigation water quality to maintain balance over time. For high‑value crops, track seasonal totals and aim for steady, moderate rates instead of large corrective applications, then confirm progress with follow‑up testing. Record dates and products to replicate successful harvests later.
It reports both. Labels use P₂O₅ and K₂O, so those are calculated directly. Elemental phosphorus uses P = P₂O₅ × 0.4364, and elemental potassium uses K = K₂O × 0.8301 for soil‑test comparisons.
Yes, if you convert liquids to grams of product applied over the area. Use the product density or label weight-per-volume to estimate grams, then enter the N–P₂O₅–K₂O percentages and total applied mass.
The calculator always normalizes to square meters internally. When you choose kg/ha or lb/1000 ft², it converts the same g/m² rate into a different display unit, so the value changes but the application intensity stays equivalent.
Add as many as you need. Each row is summed, so you can model base fertilizer, top‑dressings, and boosters together. Keep blank rows empty to avoid validation errors, and name products for clearer export reports.
Use totals to understand how much nutrient you added overall. Use per‑area rates to compare plans, follow recommendations, and scale to a different bed size. For container feeding, you can divide totals by pot count for a quick per‑pot estimate.
No. It quantifies what you applied, not what the soil already contains or retains. Pair it with periodic testing and plant observations. Adjust targets based on crop type, soil texture, rainfall, and irrigation practices.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.