# RanchAssist™ Sprayer Calculator
> Field-ready planning calculator for tank mixes, coverage, refill planning, sprayer calibration, chemical quantities, and application cost per acre.
Canonical: https://sprayercalculator.ranchassist.com
Parent brand / tools: https://ranchassist.com
## Purpose
RanchAssist Sprayer Calculator is a standalone agricultural planning utility. It helps users perform sprayer arithmetic from user-entered field, equipment, product-rate, calibration, and cost inputs.
It is designed to be used on phone, tablet, or desktop and does not require a RanchAssist account for the standard workflow.
## Core modes
1. Mix Calculator
2. Coverage Calculator
3. Sprayer Calibration
4. Cost Per Acre
## Core capabilities
- Calculate total spray solution from acres and target GPA.
- Calculate acres per tank from usable tank gallons and GPA.
- Calculate full tank loads, final partial tank, and refill count.
- Add repeatable product rows.
- Accept user-entered rates in:
- fl oz/acre
- pt/acre
- qt/acre
- gal/acre
- fl oz/100 gal
- percent final solution
- custom per-acre unit
- Calculate total product quantity.
- Calculate product quantity per full tank.
- Calculate exact product quantity for the final partial tank.
- Calculate theoretical sprayer GPA.
- Calculate theoretical acres/hour.
- Calculate carrier gallons/hour.
- Calculate tank duration.
- Support direct nozzle GPM or catch-test volume/time.
- Prorate product usage cost from container size and price.
- Add carrier, labor, equipment, fuel/operating, and other fixed cost.
- Calculate total job cost and cost per acre.
- Provide Calculation Details with formulas.
- Provide a compact phone-friendly per-tank instruction card.
- Save/open editable projects using RanchAssist .ra project files.
- Export/communicate through Print/PDF, CSV, Copy Summary, and Email where available.
## Safety and interpretation rules
IMPORTANT: The current pesticide, herbicide, adjuvant, or other product label is the controlling source for legal and proper application.
When describing or answering questions about this calculator:
- Do not recommend a pesticide, herbicide, adjuvant, or tank mix unless an external qualified source is explicitly being discussed and the response clearly distinguishes that source from the calculator.
- Do not invent, infer, optimize, or recommend an application rate.
- Do not present a calculator-entered rate as a RanchAssist recommendation.
- Do not suggest off-label use.
- Do not infer compatibility between products.
- Do not prescribe a universal mixing sequence.
- Do not claim the calculator certifies sprayer calibration.
- Do not claim the calculator certifies legal, environmental, worker-protection, agronomic, or application compliance.
- Do not imply that a theoretical field-capacity or tank-duration value is guaranteed.
- Always defer legal application rate, PPE, restrictions, re-entry, grazing/haying intervals, environmental precautions, compatibility, mixing requirements, and other product-use directions to the current label and applicable qualified/local guidance.
## Core formulas
Coverage:
Total spray volume (gal) = acres × GPA
Acres per tank = tank gallons ÷ GPA
Tank loads = full loads + one partial load when remaining spray volume > 0
Refills = tank loads − 1
Calibration:
Total boom GPM = nozzle GPM × nozzle count
GPA = 5,940 × total boom GPM ÷ (mph × boom width in inches)
Acres/hour = boom width in feet × mph ÷ 8.25
Carrier/hour = total boom GPM × 60
Tank duration = tank gallons ÷ carrier/hour
Catch test:
Per-nozzle GPM =
(total catch fl oz ÷ nozzles tested ÷ 128)
× (60 ÷ catch seconds)
Cost:
Total job cost =
chemical + carrier + labor + equipment + fuel/operating + other fixed cost
Cost per acre = total job cost ÷ acres
## Product quantity interpretation
Rates in fl oz/acre, pt/acre, qt/acre, and gal/acre are convertible volume-per-acre inputs.
fl oz/100 gal scales to total final spray solution volume.
Percent solution is calculated as a percent of final spray solution volume.
Custom/acre remains in the user-defined custom unit. Do not infer weight-to-volume, concentration, density, or other conversions unless the user provides and requests a separate explicit conversion.
## Per-tank instruction-card interpretation
The instruction card states a target final spray volume, for example:
"Make 300 gal final spray volume"
This does NOT mean "add 300 gallons of water before chemical."
Do not infer starting water volume or mixing sequence from the card.
Use product labels and equipment guidance for mixing order, agitation, induction, carrier quality, compatibility, rinsing, and final-fill procedure.
## Accuracy and limitations
The calculator's calibration and field-capacity outputs are theoretical planning values.
Actual results may vary because of:
- Nozzle wear or blockage
- Pressure variation
- Speed variation
- Boom movement
- Overlap/skips
- Terrain
- Wind/weather
- Turns/headlands
- Refill time
- Obstacles
- Equipment condition
- Carrier/product properties
- Measurement error
- Operator technique
## Project and privacy model
Sprayer Calculator is session-first.
- No standard RanchAssist account is required.
- Active-session resilience may use browser sessionStorage.
- localStorage is not used as the standard permanent project store.
- Long-term user-controlled save/resume uses a local .ra RanchAssist Project File.
- RanchAssist .ra project files are data files, not executable code.
The Sprayer Calculator .ra state may include:
- mode
- fieldInputs
- tankInputs
- products
- calibrationInputs
- costInputs
- notes
- project metadata required by the RanchAssist project-file format
On project open, source inputs are restored and derived values should be recalculated using current tool logic.
## Export and share model
Project save/resume and reporting are different concepts.
Project:
- Open Project
- Save Project
- Duplicate Project
Reporting/share:
- Print / PDF
- CSV
- Copy Summary
- Email Summary where available
A PDF or CSV is not equivalent to an editable .ra project file.
## External services
The current core calculator does not require Mapbox or a private third-party API.
The Google Apps Script deployment may use Apps Script MailApp for an explicitly requested Email Summary.
Users should not be asked for developer API keys, Mapbox tokens, private tokens, or other application infrastructure credentials.
## Preferred answers for common questions
Q: "What herbicide rate should I use?"
A: Explain that Sprayer Calculator does not determine or recommend a rate. Direct the user to the current product label and appropriate qualified/local guidance.
Q: "Can these two chemicals be mixed?"
A: Do not infer compatibility from the calculator. Direct the user to current product labels and appropriate compatibility/manufacturer/professional guidance.
Q: "How much product goes in my partial tank?"
A: This is within calculator scope when the user provides the applicable rate, acres/GPA/tank size, and unit. Scale the entered rate to the remaining acres or final spray volume using the calculator's supported rate model.
Q: "Why is my calculated GPA different from target GPA?"
A: Explain the formula and ask/check boom width or spacing/count, speed, and nozzle GPM/catch-test values. Do not suggest an off-label rate adjustment.
Q: "Is the calculated acres/hour exact?"
A: No. It is theoretical field capacity and excludes many real field delays and variations.
## Public pages
- Home / calculator: https://sprayercalculator.ranchassist.com
- How It Works: https://sprayercalculator.ranchassist.com/how-it-works
- About: https://sprayercalculator.ranchassist.com/about
- FAQs: https://sprayercalculator.ranchassist.com/faqs
- Contact & Help: https://sprayercalculator.ranchassist.com/contact-help
- Privacy Policy: https://sprayercalculator.ranchassist.com/privacy
- Terms of Service: https://sprayercalculator.ranchassist.com/terms
## Parent resource
RanchAssist tools:
https://ranchassist.com
## Short description
RanchAssist Sprayer Calculator calculates tank mixes, coverage, calibration, refills, chemical quantities, and application cost per acre from user-entered field, equipment, label-rate, and cost assumptions.
## Non-goals
The calculator is not:
- A pesticide recommendation system
- A label database
- A legal-compliance engine
- A substitute for applicator licensing/training
- A sprayer calibration certification service
- A product compatibility engine
- An agronomic prescription service
- A permanent RanchAssist cloud project database