Septic Tank Sizing Calc

Sizing a septic system and need the tank gallons and drainfield area? Set the bedroom count, type in your perc rate, and read the numbers off one screen. Everything updates as you type. WHAT YOU ENTER: - Bedrooms, 1 to 6 - Occupants (optional) — leave it blank and the flow comes from the bedroom count - Percolation rate in minutes per inch, from your perc test - Override GPD (optional) — type a daily flow and the app uses that number exactly as entered WHAT IT CALCULATES: Daily Flow: - Estimated daily wastewater flow, at 75 GPD per person Tank: - Minimum tank capacity, from the IRC Table P3007.1 minimums for your bedroom count Drainfield: - Soil absorption rate for your perc rate, with a "Not suitable" flag when the soil is outside the usable range - Required absorption area in square feet - Trench length at a standard 3 ft trench width - Number of trenches, at 100 ft maximum each KEY FEATURES: - One screen, live results, no calculate button - Metric toggle - The calculator works completely offline. No account, no login, nothing you type leaves your device - $4.99 once. No subscription, no in-app purchases READ THIS BEFORE YOU RELY ON IT: This is a fast preliminary sizing tool, not a permit submittal and not a design. - It sizes residential systems from bedroom count. It does not model commercial fixture units or usage patterns. - Local health departments set their own rules and frequently require more than the IRC minimum. Your jurisdiction wins; check it. - Trench length assumes a 3 ft wide trench. There is no trench width input. - It sizes the tank and the field. It does not suggest tank dimensions, pick a product, or lay out the field. The app also includes a More Pro Tools card linking to our other apps on the App Store. Nothing in the calculator needs it, and nothing needs a connection. Built for septic installers, civil engineers, and homeowners planning rural construction who want the first-pass number in seconds.