Gardening & Lawn Calculators
17 free gardening calculators for soil, mulch, fertilizer, seeds, plant spacing, and more. No signup required.
17 free tools
Soil Calculator
Raised bed or plot dimensions to cubic feet, cubic yards, and bags of soil.
Mulch Calculator
Area and depth to cubic yards and bags of mulch.
Fertilizer Calculator
NPK ratio and area to pounds of fertilizer needed per application.
Lawn Seed Calculator
Lawn area and grass type to pounds of seed for new lawns or overseeding.
Plant Spacing Calculator
Bed area and plant spacing to number of plants needed.
Seed Spacing Calculator
Crop type and row length to seeds needed with spacing and depth guides.
Raised Bed Planner
Raised bed dimensions to square foot grid, soil volume, and bag count.
Compost Calculator
Green and brown material amounts to carbon-to-nitrogen ratio with optimization tips.
Watering Calculator
Plant type and pot size to watering frequency and water amount.
Grow Light Calculator
Room size and plant type to total LED wattage, fixture count, and hang height.
Harvest Date Calculator
Planting date and crop type to expected harvest date and days to maturity.
Garden Bed Volume Calculator
Any bed shape and soil depth to cubic feet, cubic yards, and bag count.
Sprinkler Coverage Calculator
Lawn area and spray radius to head count and total GPM flow rate.
Greenhouse Size Calculator
Plant count and growing method to minimum area and nearest standard greenhouse size.
Tree Spacing Calculator
Plot dimensions and tree type to grid count, row count, and trees per row.
Pot Size Calculator
Plant type to recommended pot diameter, depth, gallon size, and soil volume.
Worm Bin Calculator
Weekly food waste to worm count, bin size, and starting bedding amount.
About Our Gardening Calculators
Every gardening calculator on this page is completely free, requires no signup, and runs entirely in your browser. We cover soil and mulch quantities, fertilizer application rates, seed and plant spacing, raised bed planning, composting ratios, and more.
Whether you are filling a raised bed, starting a new lawn, planning an orchard, or setting up a worm bin, these tools give you accurate material estimates instantly. All calculations update live as you type.