# Saturation Calculator — Steady-State Value Estimator

> Steady-State Value Estimator (iPhone/iPad app by Yasuo Kadoya.)

- Source: https://appshunter.io/ios/app/saturation-calculator/id6824502606 (this page in markdown: same URL + `.md`)
- Developer: [Yasuo Kadoya](https://appshunter.io/developer/6824111719)
- Category: Utilities, Productivity
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: American English, Japanese
- Released: 2026-10-26
- Data updated: 2026-10-29

## What is Saturation Calculator?

Saturation Calculator is an engineering tool that fits measurement data approaching a constant value to a first-order response model and estimates the final steady-state value.

Enter elapsed time and measured values directly on your iPhone at the plant floor, beside equipment, at a test site, or in the laboratory. Results can be checked on-site without bringing a computer, transferring measurements to a spreadsheet, or waiting until you return to your desk.

TYPICAL USE CASES

• Checking stabilization after equipment startup or warm-up
• Evaluating temperature, pressure, flow, or sensor-output responses
• Observing how a measurement approaches a stable value after a setting change
• Estimating stable values during equipment inspection and commissioning
• Analyzing response measurements in research and development
• Reviewing measurement trends in production and quality control
• Performing quick analysis where using a computer is impractical

KEY FEATURES

• Estimate the steady-state value from elapsed-time and measured-value data
• Select seconds, minutes, or hours
• Automatically handle increasing and decreasing responses
• Fit all entered data to a first-order model using nonlinear least squares
• Display clear guidance when the data cannot produce a stable fit
• Perform calculations directly on the iPhone

The free version calculates the Steady-State Value from three measurement points.

A one-time purchase unlocks the Full Version with:

• From 3 to 100 data points
• 95% Response Time
• Time Constant
• 98% Response Time
• Coefficient of determination (R²)
• A graph of measured data and the fitted curve
• Interactive inspection of the predicted value at any time on the graph

The calculation uses the following first-order model:

y(t) = y∞ + (y0 − y∞) exp(−t / τ)

The measured value at t = 0 is used as the initial value.

This app is intended for analyzing data that can reasonably be approximated by a first-order saturation response. It may not be suitable for every physical process and is not intended to be the sole basis for safety-critical decisions.

Entered measurements and calculation results are not stored permanently on the device.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Full Version | $5.99 | one-time |


## Is Saturation Calculator safe?

Not enough ratings yet to assess Saturation Calculator.

## Is Saturation Calculator legit?

Saturation Calculator has limited verification signals. The AppsHunter Legitimacy Score for Saturation Calculator is 58 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 1 release)

### 1.0 — 2026-10-27

No release notes.

## More apps by Yasuo Kadoya

- [Starry Soft Filter](https://appshunter.io/ios/app/starry-soft-filter/id6824111717)

All apps by Yasuo Kadoya: https://appshunter.io/developer/6824111719

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-29.*