My name is Chris. I’m a 5th generation farmer in the Columbia Basin, Washington State, farming potatoes, corn, and wheat on an irrigated family operation.
These tools are also used by agriculture students studying farm management, crop science, or agronomy — by rural landowners evaluating whether their land is rented at fair market value — by agronomists and crop consultants advising growers on inputs and economics — and by anyone curious about how farm economics and crop science actually work. The math doesn’t care if you farm 5,000 acres or you’re doing homework. Every calculator is free, no signup required.
I built MyFarmCalc because I got tired of the patchwork. Before this site existed, every calculation meant switching between my phone calculator, pen and paper, and a handful of spreadsheets that were clunky to use in the field. I could never find a single resource that handled the different types of calculations I actually needed. I’d find a calculator that was close enough, then go back to my phone to finish the math — or build a spreadsheet that worked fine at my desk but was useless standing next to a pivot.
I built the tools I wished already existed.
Every calculator on this site is built from published agronomic references — USDA research, WSU Extension publications, and industry standards. Formulas are cross-checked against known benchmarks. If you find a result that doesn’t match your real-world experience, let me know — accuracy matters and I’ll investigate.
Questions, bugs, or feature requests: myfarmcalc@gmail.com
Before I built MyFarmCalc, I was running numbers in spreadsheets — sometimes on paper — in the cab of a tractor or at the kitchen table late at night. The tools that existed were either buried inside paid software subscriptions, locked behind extension service logins, or simply didn’t exist for the crops and systems I was working with.
The Columbia Basin is one of the most intensively irrigated agricultural regions in the world. Pivot irrigation design, potato storage calculations, and crop water use are daily realities here. I needed tools that reflected that reality — not generic Midwest corn calculators that didn’t account for irrigated conditions, CWT pricing, or center pivot GPM requirements.
So I built them. And then I put them online for anyone who needed them.
Every calculator on MyFarmCalc is built on agronomic formulas and standards that I’ve verified against published university extension resources, USDA references, and industry standards like the TeeJet application guide, ASABE irrigation standards, and USDA grain moisture tables.
The GDD tracker uses live weather data from the Open-Meteo API — the same ECMWF ERA5 reanalysis dataset that professional meteorologists use — so heat unit accumulation is automatic and historically accurate, not an estimate. The grain storage calculator uses standard bulk density values from USDA and grain elevator industry references. The sprayer calibration tool includes a 760-entry TeeJet nozzle tip selection table covering XR, AIXR, TTI, and AI series nozzles.
Where I’ve made assumptions or approximations, I’ve documented them in the disclaimer on each page. These are planning tools, not certified engineering outputs. Always verify critical decisions with qualified agronomists or engineers.
The site was built for working farmers — but it’s used by a wider audience than I expected. Agriculture students use the break-even and cash rent calculators for farm management coursework. Rural landowners use the cash rent calculator to evaluate lease offers. Agronomists and crop consultants use the GDD tracker and sprayer calibration tools with their grower clients. Grain elevator operators use the grain drydown and storage capacity calculators. And people in countries I’ve never visited — Brazil, Germany, Kenya, India — use tools I built for a Columbia Basin operation, because the underlying agronomy is universal even when the crops and units differ.
All calculators are free. No account. No email required. No data is collected about what you calculate. The only data I see is aggregate, anonymized traffic data through Google Analytics — page views and time on site, nothing more.
If you find a bug, have a suggestion for a new calculator, or want to flag a formula that doesn’t look right — please reach out. My email is myfarmcalc@gmail.com. I read everything, though I can’t promise a fast reply during planting and harvest seasons.