Scotts Turf Builder Settings For Grass Seed
Work out your grass seed rate, the kilos and bags your lawn needs, and a weigh test that verifies your spreader's dial setting.
Calculator Inputs
The new-lawn preset (30 g/m²) and over-seeding preset (25 g/m²) come from a UK retailer spreader-settings chart checked 15 October 2026. Your own product label always overrides a preset — choose Custom rate and type the rate printed on the bag.
Add your bag weight (printed on the pack) to see how many bags to buy and what one bag covers. Leave it blank to see the total kilos only.
Weigh-test your spreader once: cover a measured strip, weigh the product that came out, and enter both figures. With your current dial number too, the calculator works out the exact dial position for the label rate. How the weigh test works.
Dial numbers are proprietary per spreader model and per product — no page can quote one universal number honestly. This tool converts the rate on your bag into the setting on your spreader.
Calculation Breakdown
| Step | Calculation | Result |
|---|---|---|
| Target application rate | Your job type or label rate | - |
| Total product needed | Area × rate ÷ 1000 | - |
| Bags to buy | Total ÷ bag weight, rounded up | - |
| One bag covers | Bag weight × 1000 ÷ rate | - |
| Weigh-test actual rate | Product used ÷ test area | - |
| Rate difference | (Actual − target) ÷ target × 100 | - |
| Suggested dial setting | Current dial × target ÷ actual | - |
Scenario Analysis: New Lawn vs Over-seeding
| Scenario | Rate | Product For Your Lawn | Bags | lb per 1,000 ft² |
|---|---|---|---|---|
| New lawn | - | - | - | - |
| Over-seeding | - | - | - | - |
| Your rate | - | - | - | - |
Over-seeding uses a thinner rate than a fresh lawn because existing grass already holds the seed bed. The kilogram column scales each rate to the lawn area you entered above.
Weigh-Test Calibration Timeline
Measure a test stripMark out a known area — 10 to 12.5 m² works well, or time one full pass of a rotary spreader's roughly 3 m strip.
Weigh the productWeigh the bag before filling, or weigh a known amount of seed into the hopper on kitchen scales.
Spread at your normal paceWalk steadily and keep the hopper more than half full — a near-empty hopper and a faster walk both thin out the rate.
Weigh what came outWeigh the bag again. The difference in grams is the product used over your measured area.
Compare and adjustGrams ÷ m² gives your actual rate. Enter it above and the calculator converts the difference into a new dial number, then re-test once to confirm.
What Is A Spreader Setting?
A spreader setting is the dial position that makes your lawn spreader release a specific weight of product over a specific area — usually written as grams per square metre (g/m²) in the UK, or pounds per 1,000 square feet on US labels. It matters because grass seed sown too thinly leaves bare patches, while seed sown too thickly competes with itself, mats together and yellows.
Why There Is No Universal Dial Number
Spreader manufacturers number their dials differently per model, and product manufacturers calibrate their charts per granule size and weight. A dial 6 on one Scotts-style spreader is not the same opening as a dial 6 on another, and grass seed — a large, light, irregular granule — flows very differently from a fine lawn feed. That is why retailer charts list a separate number for every spreader-and-product pair, and why the honest answer is the rate on your own bag plus one weigh test on your own spreader.
How The Weigh Test Works
The weigh test measures what your spreader actually puts down rather than what a chart claims. Cover a measured area, weigh the product used, and divide grams by square metres to get your real application rate. Comparing that with the label rate tells you whether your dial is right, and the proportional correction — current dial × target rate ÷ actual rate — gives the position to try next.
New Lawn Rates vs Over-seeding Rates
Sowing a bare lawn from scratch typically needs about 30 g/m² of grass seed, while over-seeding an existing lawn needs less — around 25 g/m² — because the established grass fills the gaps and dense new seed would crowd itself. If you are feeding rather than seeding, lawn feed rates are set on the feed's own label and use a different granule again, so calibrate the spreader separately for each product.
Walking Pace, Hopper Level And Overlap
Three things change your real rate between passes: walking speed (faster walking thins the rate), hopper level (a nearly empty hopper feeds less consistently), and overlap on turns. Pick one steady pace you can repeat across the whole lawn, keep the hopper topped up, and edge the lawn first so your overlap passes land on already-covered ground rather than doubling the dose on the border.
Common Spreader Mistakes
The most common errors are trusting a chart number without checking it, setting the dial while the hopper is empty and then filling, stopping walking before closing the hopper (which dumps a strip of seed), spreading in wind that carries light seed sideways, and calibrating for feed then reusing the same setting for seed. Calibrate once per product and write the number on the bag.
Frequently Asked Questions
What setting should my spreader be on for grass seed?
No page can answer that with one number: the dial scale differs per spreader model and per product. What is universal is the application rate on the label — typically 30 g/m² for a new lawn and 25 g/m² for over-seeding. Weigh-test your spreader once, compare the measured rate with the label rate, and this calculator gives you the dial number for your model.
What setting should I use on my Scotts spreader for over-seeding?
Over-seeding needs a thinner bed than a fresh lawn: 25 g/m² rather than 30 g/m². Run the weigh test at that target and the calculator converts your current dial to the right position — usually a lower number than the new-lawn setting.
Can I use Scotts Turf Builder with grass seed?
Turf Builder-type products are lawn feeds, and feed granules are a different size and weight from seed, so one dial setting does not serve both. If your plan combines them, calibrate for each product separately: run one weigh test with the seed and another with the feed, using each product's own label rate.
How do I know if my spreader is putting down too much?
Do the weigh test: cover a measured strip, weigh what came out, and divide grams by square metres. Anything more than 10% off the label rate wastes product — seed above roughly 35 g/m² mats together and yellows, and feed above its rate can scorch the lawn.
Does walking speed change the setting?
Yes. Spread rate falls as you walk faster, because the same flow covers more ground. Test at the pace you will actually walk the lawn, keep it steady, and re-test after any dial change so the two measurements are comparable.
Method and limits
The calculator converts an application rate in g/m² into total product, bags and a verified dial correction using the constants below.
- Assumes dial-to-flow is roughly proportional over the middle of the dial's range — the suggested dial (current dial × target ÷ actual) is a first-order correction that one re-test confirms; very small or very large openings can respond less linearly.
- Preset rates are reference figures, not your label — 30 g/m² new lawn and 25 g/m² over-seeding from a UK retailer spreader-settings chart (checked 15 October 2026). Your product's own printed rate overrides them.
- The lb per 1,000 ft² figure is an exact unit conversion (× 0.204816, i.e. 92.90304 ÷ 453.59237) shown only so US-labelled products can be compared; it is not a currency conversion and does not change the physical amount.
- Does not model granule size, wind, slope or spreader-pattern overlap — these change the real rate between passes in ways no dial arithmetic can capture; the weigh test at your own pace is the check that matters.
- Dial numbers are proprietary per model and product — this page never quotes a single Scotts dial number; it derives yours from measurement.
Figures checked .
Sources
- GardenHealth — Lawn spreader settings chart (30 g/m² new lawn and 25 g/m² over-seeding seed rates; checked 15 October 2026).
- Love The Garden — Lawn spreader settings (rotary spreader strip width of roughly 3 m for planning a test pass; checked 15 October 2026).
- Relentless Gardener — Best spreader settings for grass seed and lawn feed (product-specific dial figures, e.g. 6.75 for one feed, showing settings vary per product; checked 15 October 2026).
- Unit conversion 30 g/m² × 0.204816 ≈ 6.1 lb per 1,000 ft² — exact weight-and-area constants (453.59237 g per lb, 9.290304 m² per 1,000 ft²; computed 20 October 2026).
Last updated: 2026-10-20. This tool gives an estimate only from figures you enter. Always follow the application rate and instructions printed on your own product label.
Last updated: . Sowing a new lawn from seed? The turf calculator compares seeding with laying turf instead.
About this tool
Created and maintained by CoryVu. Read how we check our tools and consult the sources and assumptions on this page.
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