Check before you build
Key measurements
Plans dimensions govern — do not scale
Plan view
Typical section
Quantities estimates — confirm before ordering
Shopping list & estimated cost enter your local prices to estimate the cost
Tools & safety
Build steps
Assumptions and rules of thumb used
Important: read before building
Plan a DIY concrete pad that fits your project
Concrete Pad Planner sizes the pad under a shed, garage, hot tub, generator, heat pump, patio or RV. Enter the footprint and the planner draws a dimensioned plan and edge section, models it in 3D with a cross-section, and works out the concrete, gravel, rebar or mesh, forms and control joints. Add your local prices for a cost estimate. Everything is a preliminary DIY estimate. Your building department and, where required, an engineer set the final specification.
1. Pick the pad
Choose what it's for and enter the footprint. Sheds can also use a gravel pad or deck blocks.
2. Check the warnings
Frost, soil, vehicle loads, permits: the planner flags what needs a professional look.
3. Price it
Enter your local prices in the shopping list to see the material cost.
4. Take it to the counter
Download the PDF report and confirm the design with your building department before you build.
Frequently asked questions
How thick should a concrete shed pad be?
4" of concrete over 4" of compacted gravel is a common starting point for sheds and patios, often with a thickened edge. Garage and vehicle slabs are usually 4"–6" with rebar. Your building department or engineer sets the final requirements.
How much concrete do I need?
Length × width × thickness, plus any thickened edge, plus about 10% for waste. A 12 × 8 ft, 4" slab is about 1.2 yd³ before the edge and waste. The planner works it out in cubic yards, cubic metres and bags.
Should I use bags or ready-mix?
Over about 1 yd³ (0.75 m³), ready-mix is usually cheaper, more consistent and far less work. For small equipment pads, bags and a rented mixer are fine.
Are these plans permit-ready?
No. The planner gives preliminary, rule-of-thumb estimates for DIY planning. Confirm every specification with your local building department, and get an engineer's review where required, before you build.