GDU Calculator is the field-ready Growing Degree Unit tracker built for farmers
and agronomists. Set up your fields, enter a planting date, and the app
automatically pulls historical and forecast weather to calculate accumulated GDUs
and show you exactly where your crop stands in its growth cycle.
π± SUPPORTED CROPS
Corn, Soybean, Wheat, Barley, Oats, Canola, Flax, Sunflower, Field Peas, Dry
Beans, Sugar Beet, Potato, Alfalfa, Cool-Season Grass β and fully customizable
crops with your own base temperature and growth stages.
π WHAT IT DOES
β’ Accumulates GDUs from planting date using historical weather data
β’ Projects forward with a 7-day forecast so you can plan ahead
β’ Shows key growth stages (emergence, silking, maturity, etc.) on a live chart
β’ Supports multiple GDU calculation methods: Simple, Modified (corn), and Capped
β’ Tracks field operations β planting, herbicide, fungicide, fertilizer,
irrigation, scouting, harvest, and more β plotted right on your GDU chart
β’ Manages multiple fields, each with its own crop, planting date, and location
πΊοΈ LOCATION & WEATHER
Set a field location by searching a place name or tapping "Use My Location" for
GPS. Weather is fetched automatically from Open-Meteo's free weather API.
Optionally connect your own Ambient Weather Network (AWN) station for
hyperlocal, on-farm data.
π YOUR DATA, YOUR DEVICE
No account. No sign-up. All field data is stored locally on your device. Export
any field β or your entire farm β to a JSON file for backup or transfer. Import
it on another device in seconds.
β
DESIGNED FOR THE FIELD
β’ Works offline once weather data is loaded
β’ Dark mode support
β’ Fahrenheit / Celsius toggle
β’ Clean, fast interface built for quick daily checks
Whether you're timing a fungicide pass, watching for silk emergence, or planning
harvest logistics, GDU Calculator gives you the numbers you need β right when
you need them.