How to measure your lawn for sod, seed and fertilizer (shapes minus beds, one area for three orders)

Pace it, then tape it

Walk the lawn first and sketch it: where it is a rectangle, where it curves, what sits inside it. Then tape each part. Measure length and width in two places, because lawns are rarely square, and keep the larger figure; sod rounds up to whole rolls anyway. Write every dimension on the sketch before you open a calculator. For a round lawn or bed, measure straight across the widest point: that is the diameter. For a wedge, measure the straight edge (the base) and the distance from it to the far corner at a right angle (the height).

Split the lawn into shapes

Three formulas cover almost any lawn: a rectangle is length × width, a circle is π × (diameter ÷ 2)², a triangle is base × height ÷ 2. The example lawn is a 40 × 25 ft rectangle with a round side lawn 20 ft across and a wedge by the fence, 10 ft along the fence and 8 ft deep. Added up they make 1,354 sq ft. The sod calculator’s shape mode takes the same three shapes, as many as you need, and keeps the total for the seed and fertilizer calculators.

Take off what is not grass

Now the obstacles: the path to the shed, 3 ft wide and 30 ft long, and the bed around the tree, 8 ft across. They are shapes too, subtracted: 140 sq ft off, 1,214 sq ft left. The rule is simple: anything you would not lay sod on, sow seed on or feed comes off: a shed, a patio, a drive, a pond, a vegetable bed. A tree without a bed around it stays in the area.

Add the extra only where it belongs

Sod gets an extra for the cuts at edges, along curves and around obstacles: CT Sod, How many square feet of sod comes on a pallet says 5 to 10 percent, the calculator starts at 10%, and a plain rectangle can drop to 5%. Seed gets no extra: the rate per 1,000 sq ft (7 lb per 1,000 sq ft for tall fescue (turf-type), Penn State Extension, Lawn Establishment, Table 1) is the midpoint of a published range, and the round-up to whole bags is the only margin. Fertilizer gets no extra either: the calculator flags a nitrogen target above the extension maximum (Purdue Extension PPP-155, A Simple Procedure for Fertilizing Cool-Season Lawns: not more than 1 lb per 1,000 sq ft in a single application).

One area, three orders

The area goes into the three calculators once (they share it) and comes back as rolls, bags and pounds. Sod is the 10 sq ft roll (CT Sod, How many square feet of sod comes on a pallet), 50 to a pallet, at $9.00 a roll; seed is tall fescue (turf-type) in 10 lb bags at $53.00; the starter feed is 16-8-8 at 0.75 lb per 1,000 sq ft of nitrogen (Penn State Extension, Lawn Establishment, fertilizing at seeding) with the seed; the regular feed is 32-0-4 at 1 lb per 1,000 sq ft (Purdue Extension AY-27, Maintenance Calendar for Indiana Lawns, September), 4 times a year on the cool-season calendar, in 12.5 lb bags. The sod weighs 2,010-4,020 lb, so have it dropped next to the lawn.

You would not buy all of it: sod or seed, not both, and the starter feed only with new seed. For the sod line by lawn size see How much sod do I need for 500 square feet?; for seed by grass type How much grass seed per square foot?; for the feeds starter fertilizer per 1,000 sq ft and fertilizer per 1,000 sq ft. The Pro lawn plan puts the three orders and the 12-month calendar on one printable page.

The same lawn in metres

Switch the calculators to UK / metric and the shapes are typed in metres; the example lawn is 113 m². Turf comes in rolls of about 1 m² with 5% extra recommended (Rolawn, How to measure your lawn): 118.4 (buy 119 rolls), £584 at £4.91 a roll on their price tier for that quantity. Seed at the general-purpose lawn (ryegrass and fescue) rate of 35 g per m²: 3.95 kg, 3.9 (buy 4) boxes of 1 kg. Feed at the 6-2-4 label rate of 35 g per m²: 3.95 kg per feed, 2 feeds a year, 3 packs of 2.8 kg. The roll dimensions and the price tiers are in How many rolls of turf do I need?.

Whatever the shape, the order of operations is the same: shapes, minus obstacles, plus the sod extra, divided by the roll or the bag, rounded up. 1,214 sq ft took five shapes and a sketch.