Background Few studies mention how to objectively adjust peritoneal dialysis (PD) dwell volume (DV) for adult continuous ambulatory peritoneal dialysis patients. It requires a great deal of physicians’ precious time to determine the appropriate DV during daily practice. An app with evidence is required to solve this problem independently and efficiently This study aims to determine a method for fluid control that can reduce fluid overload-related complications. We proposed a reference equation composed of parameters from the peritoneal equilibration test (PET) for adjusting daily dialysate DV to obtain more ultrafiltration volume.Methods Ninety PD patients being treated at one medical center were enrolled, with laboratory data collected during half-yearly PET evaluations. The instilled dialysate was composed of 2.57% glucose PD fluid, either 1500 ml or 2000 ml for two groups in DV. We measured intraperitoneal pressure (IPP) before dialysate instilled (P0) and drained in the supine position after four hours (P4), effluent volume (ml), body mass index (BMI), waist circumference, and other parameters, including social demographics, to predict the appropriate DV. Exploratory factor analysis (EFA) was performed to extract independent domains. Statistical multivariate techniques of discrimination analysis and logistic regression (LR) to verify the most feasible and optimal formula were applied to determine inflow volumes for patients. A final equation for fine-tuning daily DV was proposed with an app to be used for physicians and patients in clinical settings.Results Two domains were observed by using EFA: (1) P0, and P4, and effluent volume and (2) BMI and waist circumference. We determined a formula for calculating daily dialysate DV, derived from Logistic analysis to obtain an accurate prediction rate of 94.44% with Z = 4.32974 + 3.85477 * F1 + 3.83008 * F2, higher than the previous study at 80.68%. An app was created to easily adjust the DV in the daily procedure.Conclusion The novel formula, combined with an app using objective, real-time parameters for predicting appropriate DVs, was proposed for PD patients to optimize maximal ultrafiltration volumes and reduce subjective abdominal discomfort. DV is easy to calculate using the app, which makes it possible for physicians or patients to make frequent adjustments.