Septic tools

Free, no signup, nothing sent anywhere. Each tool publishes its assumptions.

The tools

Septic problem checkerTick what you're seeing. Ranks the likely causes — full tank, blocked baffle or filter, pump, drain field or just the weather — and says who to call first.Septic system cost calculatorA planning range for a new or replacement system from type, bedrooms, soil and region — then check a quote for price and scope red flags.Septic tank size calculatorThe minimum tank for your bedrooms under the model code, with the garbage disposal allowance, the size you'd actually buy and the design flow.Septic pumping schedule calculatorYears between pump-outs for your tank size and household, from the Penn State extension table, with the garbage disposal adjustment.

Which one to start with

If something is wrong right now — slow drains, a backup, a smell, an alarm — start with the problem checker. It separates a full tank or a clogged line from a failing drain field, which is the difference between a few hundred dollars and several thousand.

If you’re building, replacing a system or holding a quote, use the system cost calculator. It prices the job line by line from the system type, bedrooms and soil, and checks a quote for the gaps septic quotes most often have: no perc test, no permit, an undersized tank, or a replacement nobody has proved is needed.

For planning, the tank size calculator gives the code minimum for your bedrooms, and the pumping schedule tells you how often your household needs the tank emptied.

How these differ from a septic company's calculator

Most septic calculators online belong to companies that sell the installation, and ask for a phone number before showing a number. These don’t ask for anything, and will tell you when the answer is to pump the tank or clean a filter rather than replace the field.

Every assumption, written down

What happens to what you enter

Nothing leaves your browser. The tools run entirely on your device, there’s no account and no form that sends your details to a contractor, and the results aren’t saved anywhere once you close the page.

What to have in hand

For the problem checker: which drains are affected, when the tank was last pumped, and what the ground over the field looks like.
For the cost calculator: bedrooms, the system type from the perc test or soil report if you have one, and the quote total and tank size.
For the tank size calculator: bedrooms, and whether there’s a garbage disposal.
For the pumping schedule: the tank size from a pumping receipt or the permit record, and how many people live in the house.