4 tools
Lawn & Garden calculators
Lawn & Garden calculators: Order mulch, topsoil, gravel, sand, seed and sod, and plan fertilizer and watering for a yard.
Bulk material needs area and depth; mass also needs measured density. Seed, fertilizer and watering scenarios require product labels, grass type, soil, rainfall and local conditions.
Grass Seed Calculator
Buy the right amount of seed for a new lawn or an overseeding job.
Inputs: Lawn area (sq ft), Seeding rate, Bag size (lb)
Open calculator →02Lawn Fertilizer Calculator
Apply the labeled amount of nitrogen and no more, whatever the bag's strength.
Inputs: Lawn area (sq ft), Nitrogen to apply (lb per 1,000 sq ft), Nitrogen in the bag (%), Bag weight (lb)
Open calculator →03Sod Calculator
Order enough sod to finish the job in one delivery, because it must be laid fresh.
Inputs: Area to cover (sq ft), Sod roll size (sq ft), Waste allowance
Open calculator →04Lawn Watering Calculator
Turn an inch of water a week into the minutes to run a sprinkler.
Inputs: Lawn area (sq ft), Water needed per week (in), Sprinkler output (gallons per minute)
Open calculator →Lawn & Garden calculator results and examples
| Calculator | What it answers | Headline output | Worked example |
|---|---|---|---|
| Grass Seed Calculator | Buy the right amount of seed for a new lawn or an overseeding job. | Seed needed (lb) | 30 |
| Lawn Fertilizer Calculator | Apply the labeled amount of nitrogen and no more, whatever the bag's strength. | Fertilizer needed (lb) | 25 |
| Sod Calculator | Order enough sod to finish the job in one delivery, because it must be laid fresh. | Rolls needed | 126 |
| Lawn Watering Calculator | Turn an inch of water a week into the minutes to run a sprinkler. | Water per week (gallons) | 1,869 |
Where people go wrong with lawn & garden numbers
For an assumed 1,000 ft² area and 2 in depth, bulk volume is 166.667 ft³ or 6.17284 yd³ before allowance. One inch of applied water over that area is about 623.38 gallons, not a universal weekly prescription.
Lawn & Garden: related calculator categories
Common lawn & garden questions
How many square feet does a cubic yard cover?
A cubic yard covers 324 square feet at 1 inch deep, 162 at 2 inches, 108 at 3 inches and 81 at 4 inches. The calculator does this for any area and depth
Is it cheaper to buy in bulk or in bags?
Usually bulk once you pass about a cubic yard, which is 13 or 14 two-cubic-foot bags. Bags cost more per yard but are easier to carry and store, and bulk needs a delivery spot
Do bulk materials settle after delivery?
Yes. Soil and mulch settle by 10 to 20 percent and stone compacts by about 10 to 15 percent, so round the order up rather than down
Why is the tonnage different from what I expected?
Bulk weight depends on the actual material, moisture and compaction. Gravel assumptions of 1.3–1.6 short tons per cubic yard, sand assumptions of 1.3–1.4 and a topsoil assumption of 1.1 are comparison inputs, not measured supplier values. Added water increases mass without supplying one universal wet-density conversion
How much water does a lawn need?
Choose a depth using the site’s grass, soil, weather, rainfall and local watering restrictions. The volume tool converts the entered depth over an area; it does not prescribe a universal schedule. Check infiltration and runoff rather than assuming repeated calendar watering reaches the root zone.
How do I read the numbers on a fertilizer bag?
They are the percent nitrogen, phosphorus and potassium by weight. A 20-5-10 bag is 20 percent nitrogen, so 15 pounds of it holds 3 pounds of nitrogen
When is the best time to seed a lawn?
Planting timing depends on the grass species, soil conditions and local climate. Follow the selected seed label and locally applicable extension guidance. Germination and establishment requirements vary, so do not assume every seed mixture needs the same number of weeks or watering pattern.
Do these calculators handle sloped or curved beds?
They use a flat area you enter. For a curve, split the bed into rectangles and circles, add their areas, and add 5 to 10 percent for the awkward edges
How much mulch do I need for a garden bed?
Multiply bed area by the selected depth after converting inches to feet, then divide cubic feet by twenty-seven to obtain cubic yards. Choose depth from the material and planting requirements. Keep material clearances and compaction separate from the geometric volume estimate.
How much water does a lawn need per week?
About one inch, counting rain, and more in hot dry weather, which the Lawn Watering Calculator converts to gallons and sprinkler time
How do I know how many rolls of sod to buy?
Measure the treatment area, apply an explicit layout allowance and divide by the supplier’s actual roll coverage. Round up to whole rolls. Roll sizes and waste needs vary; check the grower’s product information rather than assuming every roll covers the same area.
How deep should mulch be?
About 2 to 3 inches for most beds. Under 2 inches lets weeds through, and over 4 inches can smother roots and hold too much moisture. Keep it a few inches back from trunks and stems.