Fertilizer and seed quantity calculator
Enter the length and width of the area, then type the application rate read on the bag of the product you use. The calculator returns the area and the total amount of product, in pounds or in kilograms.
To get a number of bags, type the weight of the bag you plan to buy. Leave that field empty if you only need the amount.
Enter your measurements and the rate, then calculate.
Method and limitations
Area = length × width. Imperial: the application rate is in pounds per 1,000 sq ft, so the amount in pounds = area ÷ 1,000 × rate. Metric: the application rate is in grams per square meter, so the amount in kilograms = area × rate ÷ 1,000. Bags = amount ÷ weight of one bag, rounded up to a whole bag; the bag weight is the one you read on the label, in pounds (imperial) or kilograms (metric). The application rate and the bag weight depend on the product and on the plant, so none is assumed: type the ones printed on the bag. The result is the amount for a flat rectangle, applied evenly: overlaps, uneven ground and spreader settings are not computed. This is an arithmetic calculation, so no external source is needed.
Sources
No external reference is documented for this calculation; its method and limitations are described above.
