Commercial and industrial water treatment decisions come down to numbers. Use these free calculators to size your RO system, estimate permeate quality, and project membrane replacement schedules — no login required.
Calculator 1: RO Permeate TDS Estimator
Estimates the TDS of RO product water based on feed water TDS and membrane rejection rate. Use this to verify whether a proposed RO system will meet your target permeate quality.
TDS Rejection Calculator
Calculator 2: RO System Flow Rate & Capacity Converter
RO systems are rated in gallons per day (GPD) but operational planning often requires GPM, LPH, or m³/day. This converter handles all common unit conversions plus temperature derating — because a system rated at 2,000 GPD at 77°F produces significantly less in cold climates.
Flow Rate Converter + Temperature Derating
Calculator 3: RO Membrane Life Estimator
RO membranes typically last 3–7 years in commercial applications, but actual life varies widely based on feed water quality, pre-treatment, operating pressure, and maintenance practices. This estimator projects membrane replacement interval and cumulative replacement cost.
Membrane Life & Replacement Cost Estimator
About These Calculators
These calculators use industry-standard formulas and FILMTEC™ membrane performance data. Results are estimates based on standard operating assumptions:
- TDS rejection calculator: Assumes new membrane at rated rejection; single-pass RO; 75% system recovery for concentrate TDS estimate.
- Flow rate converter: Temperature derating uses the standard TCF (Temperature Correction Factor) approximation of ~3% output change per degree Fahrenheit from 77°F. Actual TCF varies by membrane model.
- Membrane life estimator: Based on typical commercial installation data. Actual life depends on specific water chemistry, operating pressure, and maintenance program — a formal FILMTEC™ system design using the ROSA software tool provides more precise projections for critical applications.
Need a system sized for your specific application? These calculators give you ballpark numbers — a complete system specification requires a water test and engineering review. Contact AMPAC USA with your daily water demand, feed water source, and target permeate quality. We provide a complete system specification and quote within one business day.
Related: Commercial RO Buyer’s Guide | RO Maintenance Guide | Commercial RO Systems