TOOLS

Free calculators for planning a raw parcel

Built for Arizona conditions and checked against the state tables and NOAA. No signup, no email gate.

Arizona septic tank & leach field sizer
Tank size by bedrooms and trench length by soil percolation rate, using the tables in A.A.C. R18-9-A312 and A314.
Off-grid solar array & battery sizer
Daily load, sun hours, inverter efficiency and depth-of-discharge to array watts and battery kWh.
Battery bank autonomy
How many cloudy days a bank carries a given load.
Rainwater catchment
Roof area and annual rainfall to gallons per year, with a 0.90 collection efficiency.
Cistern sizing
Daily use, days of reserve and refill interval to a tank size and the number of standard tanks.
Driveway cut and fill
Length, width, grade change and side slopes to cubic yards of cut and fill.
Solar panel tilt by latitude
Fixed, seasonal and monthly tilt angles for your latitude.
Sun elevation, azimuth, sunrise and sunset
NOAA solar-position algorithm for any date and location — for siting a house or array.
Cabin build cost (rule of thumb)
Square footage and finish level to a planning-grade cost range. Not a bid.

Calculators give planning numbers, not designs. Septic systems in Arizona are permitted by the county or ADEQ on a site-specific soil evaluation; solar and structural work is the licensed designer’s call.