Convert between different units of fertilizer application rates for optimal crop nutrition
This tool helps farmers, gardeners, and landscapers convert fertilizer application rates between different measurement systems. Whether you're reading an international farming guide, buying fertilizer in different units, or planning applications for different sized areas, this converter makes sure you apply the right amount. For related material measurements, you might also find our construction material density converter useful for comparing bulk densities.
Converting bag instructions (usually in lb/1000ft²) to your actual garden size in square meters. A 5lb bag covering 1000ft² equals about 24g/m².
When a European seed supplier recommends 150 kg/ha but your equipment is calibrated in lb/acre. You'll need about 134 lb/acre.
Fruit trees often need precise amounts. Converting from per-tree recommendations to area-based rates for efficient spreading. For more on mass calculations, the mass and weight converter can be helpful.
Organic amendments (compost, manure) often come with different unit recommendations than synthetic fertilizers.
Multiply by 0.89
100 kg/ha ≈ 89 lb/acre
Multiply by 1.12
100 lb/acre ≈ 112 kg/ha
Divide by 305
30 g/m² ≈ 0.1 oz/ft²
Turn your phone sideways for better visibility of conversion results when working in the field. Use the "Save Conversion" button to record rates for different crop zones.
Q: Why are my converted numbers slightly different from other calculators?
A: Different conversion factors exist (exact vs. approximate). We use precise agricultural conversion factors. For most practical purposes, small differences won't affect plant growth.
Q: Should I convert N-P-K values or total product weight?
A: Always convert the actual product weight unless specifically working with nutrient content. Most recommendations are for total fertilizer product.
Q: How accurate do I need to be?
A: Within 5% is fine for most applications. Plants are forgiving, but consistent under or over-application causes problems.
If you're working with liquid fertilizers, you may also need to check the specific gravity of your solution to ensure accurate volume-to-weight conversions. For large-scale field applications, understanding the pressure in your irrigation system can help you calibrate liquid injection rates more precisely.
This converter provides mathematical conversions only. Actual fertilizer requirements depend on:
Always consult local agricultural extension services or agronomists for site-specific recommendations. Last updated: November 2025. Conversion factors based on standard agricultural references.