Calibrate spreaders and sprayers with confidence always. Enter area, choose units, and set label rate. Get exact product amount, water volume, and budget quickly.
| Scenario | Area | Label rate | Basis | Buffer | Efficiency | Typical output |
|---|---|---|---|---|---|---|
| Small lawn | 5,000 sq ft | 3.0 lb | per 1000 sq ft | 5% | 100% | ≈ 15.75 lb product |
| Medium lawn | 0.25 acre | 50 lb | per acre | 5% | 95% | ≈ 13.82 lb product |
| Garden beds | 200 sq m | 250 g | per 100 sq m | 3% | 100% | ≈ 515 g product |
This calculator converts your area into the label’s basis units and multiplies by the label rate. It then adjusts for buffer and calibration efficiency.
Pre-emergent performance begins with correct area. Measure lawns as rectangles, triangles, or circles and sum sections. For curved borders, pace the length and average the width. For beds, measure each zone and subtract patios, sheds, and paths. Convert units consistently so purchasing and application match. Mapping sprinkler zones helps keep each treatment area aligned with the plan.
Product labels express rates per 1,000 square feet, per acre, or per 100 square meters. Enter the same basis in the calculator and keep the rate unit exactly as stated. Granular products usually list mass, while liquids list volume of concentrate per area. Some labels provide a range by soil type or weed pressure; select the recommended rate for your site, then document the choice.
Spreaders and sprayers rarely deliver perfectly. Use the efficiency setting to adjust for real output, based on a catch test or calibration run. Weigh granules collected from a known area, or time sprayer output into a marked container. A small buffer can cover overlap at edges, but too much increases risk to turf and ornamentals. Recheck settings after changing walking speed, nozzle type, pressure, or granule size.
For liquid applications, carrier water affects coverage, not chemical rate. Use the carrier rate to plan total water needed for even distribution across the target area. Maintain agitation, and strain mixes to protect nozzles. Spray in parallel passes with steady pace, avoiding windy conditions. For granular products, carrier is unnecessary, but a consistent spread pattern and overlap control are critical.
Record date, product, rate, weather, and irrigation timing after application for crews. Many pre-emergents need watering-in to activate, while heavy rain can cause runoff. Avoid treating saturated soils, slopes before storms, or areas draining to open water. Respect label restrictions for edible beds, pets, and re-entry intervals. Sound records also simplify follow-up decisions and help evaluate control results next season.
Label basis is the area unit the rate is written for, such as per 1,000 sq ft, per acre, or per 100 sq m. Match it to the product label before calculating.
Efficiency adjusts the result for real equipment output. If your spreader applies 10% light, enter 90%. The calculator increases product needed to hit the label rate on the ground.
No. Carrier water affects coverage and spray quality, not the amount of active ingredient per area. Keep the label rate constant and use carrier volume to distribute it evenly.
Many products need light irrigation to move granules off leaves and activate the barrier in the top soil. Follow label timing and avoid heavy watering that could cause runoff.
Enter the package size and unit. The tool converts common mass units and rounds up to whole packages. Add cost per package to estimate a simple material budget.
Some products restrict use around edibles or require specific setbacks. Always read the label for site limitations and re-entry guidance. If unsure, treat only approved areas or choose an allowed product.
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.