Garden Landscaping Project — Materials Planner

Turf, Gravel, Mulch, Decking, Fence and Concrete Post Calculators

A garden landscaping project goes wrong most often at the ordering stage: too little gravel, a lorry load of spare topsoil, or a weekend lost to a second trip for posts. These ten calculators size every material from one set of measurements, in the order the work is done.

The tools, in order

  1. Garden Area Calculator

    Measure the garden and each bed so every later quantity starts from real areas.

  2. Turf Calculator

    Work out how many rolls of turf cover the lawn area, with a little spare for cuts.

  3. Grass Seed Calculator

    Or price seeding the lawn instead, which is cheaper but slower to establish.

  4. Raised Bed Soil Calculator

    Size the soil for raised beds, which take far more than people expect.

  5. Compost Calculator

    Work out the compost to dig into the beds before planting.

  6. Mulch & Topsoil Calculator

    Cover the beds with mulch at the right depth to keep weeds down and water in.

  7. Gravel & Sand Calculator

    Order gravel for paths and patios by depth, area and material.

  8. Decking Calculator

    Count boards, joists and screws for a deck before you go to the timber yard.

  9. Fence Calculator

    Count posts, panels or rails for the boundary run.

  10. Concrete Post Hole Calculator

    Work out the concrete to set each fence or deck post.

Measure once for the whole garden landscaping project

Draw a rough plan and measure each area separately: lawn, beds, paths, patio and deck. Every later calculation is an area times a depth, so accurate areas save money on every material. Irregular shapes can be split into rectangles and triangles and added together, which is what the garden area tool does.

Depth is where orders go wrong

Loose materials are sold by volume or weight, so the depth you choose matters as much as the area. Mulch is usually laid around five to eight centimetres deep, decorative gravel a few centimetres, and path gravel deeper over a compacted base. Doubling the depth doubles the order, so decide on depth before you compare prices.

Work in the right order

Do the hard landscaping first: posts, fences, decking and paths, since that work tramples everything around it. Then prepare the beds with compost and soil, plant, and finish with mulch. Lay turf or sow seed last so the lawn is not walked on while the rest of the garden is being built.

FAQ

How much mulch do I need for my garden beds?

Multiply the bed area by the depth you want, then convert to bags or bulk volume. A depth of around five to eight centimetres suppresses weeds without smothering plant stems. The mulch calculator does the conversion and tells you how many bags to buy.

Should I lay turf or sow grass seed?

Turf gives a usable lawn in a few weeks and hides weeds straight away, but costs much more and must be laid within a day of delivery. Seed is cheap and suits awkward shapes, but needs weeks of watering and protection before it can be walked on regularly.

How much concrete does a fence post need?

It depends on the hole size and post size, since the concrete fills the gap around the post. A common rule is a hole about three times the post width and a third of the post's height deep. The post hole calculator gives the volume and bags per post.