Fertilizer Rates: Weighing the Right Amount
Fertilizer is one job where more is not better. This post shows the area-times-rate maths and why the label is the authority.
What is the Fertilizer Calculator?
Enter the area and the application rate in grams per square metre, and the tool multiplies them into a total weight in kilograms, with a note to follow the product label. Over-application can damage plants, so the label rate matters more than any calculator.
How to use it
- Measure the area in square metres.
- Enter the label application rate in grams per square metre.
- Click Calculate Fertilizer.
Worked example
100 sq m at 30 g per square metre needs 3 kg of fertilizer.
Can I apply fertilizer twice at half rate?
Sometimes, yes, split applications can be gentler, but only if the product label allows that approach.
Frequently asked questions
Does rain wash fertilizer away?
Heavy rain soon after application can move fertilizer off target, so check the label's weather advice.
Should I water after feeding?
Many granular products need watering in; the label will say.