# Turf: Lawn Care Calculator — Fertilizer, seed & soil math

> Fertilizer, seed & soil math (iPhone/iPad app by Roman Kopaliani.)

- Source: https://appshunter.io/ios/app/turf-lawn-care-calculator/id6784354608 (this page in markdown: same URL + `.md`)
- Developer: [Roman Kopaliani](https://appshunter.io/developer/1635315269)
- Category: Utilities, Lifestyle
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: American English
- Released: 2026-06-30
- Data updated: 2026-08-20
- User reviews in markdown: https://appshunter.io/ios/app/turf-lawn-care-calculator/id6784354608/reviews.md

## What is Turf?

Turf is the lawn-care calculator that doesn't sell you fertilizer. Most "lawn apps" are a funnel for one brand's products — Turf is a neutral, citation-backed tool that just does the math: how much nitrogen, how much seed, how much lime, what spreader setting, what dilution. Every number cites a named university turf-extension source. No account, no ads, no subscription, works offline.

NITROGEN RATE (FREE, FOREVER)
Enter your bag's N-P-K analysis, your target nitrogen rate, and your lawn size. Turf returns pounds of product per 1,000 sq ft and for the whole lawn, bags needed, and a slow-release advisory — with a hard guardrail if you exceed the roughly 1.0 lb N per 1,000 sq ft single-application cap (Purdue, Virginia Cooperative Extension). The hero calculator is free forever, at full citation quality.

TURF PRO (ONE-TIME $4.99, NO SUBSCRIPTION)
A single $4.99 purchase unlocks the other five calculators — pay once, keep forever, restore across your devices:

- Spreader calibration — the weigh-back method to dial any spreader to your target rate, because the settings printed on the bag are starting points, not guarantees (Penn State).
- Liquid dilution / tank-mix — convert a product's label rate into ounces per gallon and per 1,000 sq ft, driven by your real, measured sprayer output (US EPA, extension calibration method).
- Lime & sulfur pH amendment — pounds per 1,000 sq ft to raise pH with lime or lower it with elemental sulfur, by soil texture (sand / loam / clay), with per-application caps (Michigan State, Penn State, Clemson HGIC, University of Minnesota, NC State).
- Grass seed rate — pounds of seed per 1,000 sq ft, new seeding vs. overseed, by species: KBG, tall fescue, perennial ryegrass, fine fescue, bermuda, zoysia, centipede (Penn State, Cornell, Texas A&M).
- PGR growing-degree-day timing — accumulate GDD to time your next Primo Maxx / T-Nex (trinexapac-ethyl) application, on the Kreuser & Soldat model.

HONEST BY DESIGN
Turf shows its work and flags what's disputed. The popular "sand 25 / loam 75 / clay 100" lime table isn't in any primary extension publication, so Turf uses the documented turf topdress band instead — and tells you so. The 200-GDD PGR target is validated for golf putting greens, not home lawns, so Turf says that plainly rather than pretending it's universal. For any pesticide or plant-growth regulator, the law is the product label.

SOURCES
Purdue Turfgrass, Virginia Cooperative Extension, Clemson HGIC, Penn State Extension, Michigan State University, University of Minnesota, NC State, Cornell, Texas A&M AgriLife, US EPA, and Kreuser & Soldat (PGR growing-degree-day model).

DISCLAIMER
Turf is an educational reference calculator, not professional agronomic or pesticide-application advice. Always follow the product label and confirm rates with your local cooperative extension office. For any pesticide or plant-growth regulator, the label is the law: it is a violation of federal law to use a product in a manner inconsistent with its labeling (US EPA).

Free download includes the full nitrogen-rate calculator. Turf Pro is a single one-time purchase ($4.99) that unlocks spreader calibration, liquid dilution, lime & sulfur, seed rate, and PGR timing. No subscription, no ads, no account.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Turf Pro | $4.99 | one-time |



## Version history (last 3 releases)

### 1.2 — 2026-08-15

Maintenance update. No feature changes.

### 1.1 — 2026-07-16

The number keyboard now has a Done button, so you can dismiss it when you're finished. Thanks to everyone who wrote in about this.

### 1.0 — 2026-07-01

No release notes.

## More apps by Roman Kopaliani

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- [Pond: Koi Chemistry](https://appshunter.io/ios/app/pond-koi-chemistry/id6777459595)
- [Watt: Solar for Van & RV](https://appshunter.io/ios/app/watt-solar-for-van-and-rv/id6777471058)
- [Saline: Saltwater Pool Calc](https://appshunter.io/ios/app/saline-saltwater-pool-calc/id6777715538)

All apps by Roman Kopaliani: https://appshunter.io/developer/1635315269

## Related topics

[turf pro estimator](https://appshunter.io/ios/topics/turf-pro-estimator) · [gci turf calculator](https://appshunter.io/ios/topics/gci-turf-calculator)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-20.*