Chemcalc

ChemCalc is an agricultural spray rate calculator built for NZ and AU farmers, contractors, and agronomists. It helps you select an agrichemical product, choose a target weed/pest/disease and an application method, then calculate the correct amount of product and water needed for the job using label-based rates.

Instantly turn your calculated job into a printable declaration with required shipping data.

The app includes a searchable chemical product database with key product details such as active ingredient and units. For supported products, it shows target-specific rates (including min/max ranges where available) and supports common application scenarios including boom spraying, aerial application, and handgun/handheld mixing rates (for example per hectare or per 100L of water). ChemCalc handles common units and conversions (mL, L, g, kg) and presents clear mixing outputs to reduce mistakes.

ChemCalc also provides access to product label PDFs for reference. Labels download when viewed and are cached on the device for faster repeat access. Rate data used for calculations is stored locally so you can keep working even with limited connectivity.