---
title: "Grass seed calculator"
description: "Calculate how much grass seed you need for a new lawn or overseeding. Rates are extension-style ranges in lb per 1,000 sq ft, converted for your lawn size."
slug: grass-seed
canonical: "https://lawncarejournal.app/tools/grass-seed/"
markdownMirror: "https://lawncarejournal.app/tools/grass-seed.md"
---

# Grass seed calculator

Calculate how much grass seed you need for a new lawn or overseeding. Rates are extension-style ranges in lb per 1,000 sq ft, converted for your lawn size.

## Summary

Estimate seed needed for a new lawn or overseeding by grass type and area.

## Disclaimer

Rates are approximate ranges summarized from university extension guidance—not agronomic advice for your site. Adjust for germination %, seed quality, and local recommendations. St. Augustine is typically established with sod or plugs, not seed.

## How to use

Open the interactive calculator at https://lawncarejournal.app/tools/grass-seed/. Results are estimates for DIY planning—verify product labels and local extension guidance before applying anything.

## Related guides

- [Still dormant?—green-up before Labor Day](https://lawncarejournal.app/articles/cool-season-still-dormant-green-up-gate-late-august-execute-triage.md): Late-August DIY green-up gate for cool-season lawns (tall fescue, Kentucky bluegrass, perennial ryegrass, fine fescue) that are still summer-dormant when Labor Day aerator, fertilizer…
- [Overseed vs renovate mid-August](https://lawncarejournal.app/articles/cool-season-overseed-vs-renovate-mid-august-decision-triage.md): Late-August DIY fork for cool-season lawns heading into September establishment: Kansas State Turf Blog Aug 12, 2026 Fall Turfgrass Renovation piece—moderate summer thinning often needs overseeding while severe thinning…
- [Cool-season overseed seeding rates](https://lawncarejournal.app/articles/cool-season-overseed-seeding-rates-how-much-seed.md): Late-July DIY bag math for cool-season fall overseed: Nebraska and K-State often cut overseed to about half of new-lawn rates (tall fescue overseed ~3–4 lb / 1,000 vs new ~6–8…
- [Thatch, slit seeder, or aerator?](https://lawncarejournal.app/articles/cool-season-overseed-thatch-slit-vs-aerator-mid-august-execute-triage.md): Mid-to-late August DIY execute fork for cool-season overseed after Path B is chosen: K-State McKernan Aug 14, 2026 stressed-lawn relief note—mow short about 1–1½ in and bag clippings; thatch ≤ ~¼ in can overseed…
- [Overseed watering first 14 days](https://lawncarejournal.app/articles/cool-season-overseed-irrigation-first-14-days.md): Late-August DIY watering playbook for cool-season fall overseed before Labor Day seeding: Iowa State keep the upper ~1 in moist with light, frequent water (often 1–2×/day…
- [Slit seed vs broadcast overseed](https://lawncarejournal.app/articles/cool-season-slit-seed-vs-broadcast-overseed.md): Late-July decision guide before mid-August–mid-September cool-season overseed: Iowa State seed-to-soil contact via hollow-tine aeration (~20–40 holes/ft², 3–4 passes) then drop-seed and drag cores…
- [Overseed roller vs drag mat](https://lawncarejournal.app/articles/cool-season-overseed-roller-vs-drag-mat.md): Late-July DIY contact choice after cool-season broadcast or aerate-and-seed: Iowa State—after hollow-tine aeration and drop-seeding, drag with chain-link fence or a drag mat so cores break up and mix seed into soil…
- [Straw vs germination blankets](https://lawncarejournal.app/articles/cool-season-overseed-straw-mulch-vs-germination-blanket.md): Late-July DIY shopping companion for cool-season fall overseed cover: Iowa State and Purdue AY-3—clean weed-free straw at about one bale per 1,000 sq ft so ~50% of soil stays visible (too thick smothers seedlings and ma…
- [Cool-season seed & aerator countdown](https://lawncarejournal.app/articles/cool-season-seed-aerator-early-august-countdown-triage.md): Late-August DIY countdown that pairs cool-season grass-seed shopping with hollow-tine aerator / slit-seeder rental booking before the Labor Day / September rush: Iowa State mid-August–mid-September overseed framing…
- [Fall overseed vs preemergence](https://lawncarejournal.app/articles/fall-aerate-overseed-vs-preemergence-broadleaf-sequencing.md): Cool-season fall weekends collide: core aeration plus overseeding, early–mid September winter-annual preemergence (henbit/chickweed), and late October–early November broadleaf sprays…
- [First mow after cool-season overseed](https://lawncarejournal.app/articles/cool-season-first-mow-after-overseed-seedling-traffic.md): Late-July planning bridge for tall fescue, Kentucky bluegrass, perennial ryegrass, and fine fescue after fall overseed: Iowa State mow when seedlings reach ~3 in at 2–2.5 in with a sharp blade (if ≥4 in…

Agent map: https://lawncarejournal.app/llms.txt
Tools index: https://lawncarejournal.app/tools.md