LawnsCal UK is a free, no-login calculator platform helping UK homeowners, groundskeepers and landscapers work out exactly how much grass seed, fertiliser and lawn care product they need — every time.
Buying the wrong amount of grass seed or fertiliser wastes money. We built a single, reliable place to get the right quantity — fast, free, and built around UK product sizes and sowing rates.
Most lawn-care bag labels show a rate range (e.g. 35–50 g/m²) without helping you translate that into a real bag count for your specific garden. LawnsCal UK bridges that gap — you enter your area and conditions, we tell you exactly how many kilograms and bags to buy.
Every calculator on this site is completely free to use. No registration, no paywall, no data collection. Our tools are funded by discreet, relevant advertising so they can remain free for everyone.
Every calculator is purpose-built for a specific UK lawn task. Pick yours below and get an instant, accurate result.
Work out kg of ryegrass seed for new lawns or overseeding at UK industry rates of 35–50 g/m².
Covers all common UK lawn mixes — fine fescue, bent, ryegrass blends — with adjustable g/m² rates.
All MixesCalculate seed for thin, patchy or scarified UK lawns using 15–35 g/m² overseeding rates.
Find the right kg of spring, summer or autumn fertiliser for your lawn size and nutrient goals.
FeedingMeasure rectangular, L-shaped or irregular lawn areas in m² or ft² — copy the result directly into any other tool.
NewCalculate bags of lawn top dressing or sand needed based on area and recommended depth (3–6 mm).
RenovationWork out selective weedkiller dilution volumes and total product required for broadcast or spot treatment.
Weed ControlCalculate how many rolls of UK turf you need (standard 1 m² rolls) including a wastage allowance for cuts and curves.
TurfingEstimate litres of water required per week for new seedlings or established UK lawns during dry periods.
NewEvery LawnsCal UK tool follows the same simple four-step process so you get a reliable answer in under a minute.
Pick the tool that matches your task — seeding, fertilising, turfing or top dressing.
Type your lawn's length and width, or enter the total m² directly if you already know it.
Choose your project type (new lawn, overseeding, repair) and the tool auto-sets UK-standard rates.
Instantly see your total kg needed plus bag counts for 5 kg, 10 kg and 20 kg sizes — ready to shop.
LawnsCal UK is an independent, editorially led web project. Our content and calculations are produced by lawn-care enthusiasts and checked against established UK industry sources.
Every seeding rate, fertiliser application figure and coverage table published on LawnsCal UK is cross-referenced with UK amenity seed supplier guidelines, BSPB (British Society of Plant Breeders) data, and Royal Horticultural Society recommendations before publication.
LawnsCal UK does not favour any specific grass seed brand or product. Rate tables and bag-size examples use generic industry-standard figures so the results work equally well whether you buy from a local merchant, garden centre or online retailer.
Common questions about who we are, how our calculators work and how to get the most from the site.
Choose a free calculator, enter your lawn size, and get an instant bag count — no sign-up, no cost, no guesswork.
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