# Keystone Pump TDH Calculator vs DP

The clearest difference is rating: Keystone Pump TDH Calculator at 5.0 against DP's 4.0. Keystone Pump TDH Calculator also leads on update cadence (every 6 months vs every 16 months). DP's advantage is device support (3 vs 1) and iOS requirement (13.0 vs 17.6). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Keystone Pump TDH Calculator holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

Keystone Pump TDH Calculator ships an update every 6 months, DP every 16 months. The most recent releases landed on May 31, 2026 and July 9, 2026 respectively.

## The numbers

| Metric | Keystone Pump TDH Calculator | DP |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/keystone-pump-tdh-calculator/id880925443/reviews)** | [4.0 (1 ratings)](https://appshunter.io/ios/app/dp-select/id934888136/reviews) |
| Number of ratings | 1 | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 months** | Every 16 months |
| Monetization | Free | Free |
| Size | 3 MB | 15 MB |
| Requires iOS | 17.6 | **13.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Keystone Pumps LTD](https://appshunter.io/developer/435839301) | [DP Pumps](https://appshunter.io/developer/934888135) |

## What reviewers say

### Keystone Pump TDH Calculator

[App page](https://appshunter.io/ios/app/keystone-pump-tdh-calculator/id880925443)

This utility app assists engineers and technical personnel in calculating system parameters for slurry pipe and pump sizing. It computes required head pressure and limiting settling velocity based on user-inputted system data. The tool aims to simplify the selection process for slurry pumps.

**Highlights:** Slurry Density Calculation, Limiting Settling Velocity Calculation, Slurry Head & Equivalent Water Head Calculation, Pipe Type and Size Database, NPSHA Calculation, US and Metric Units, Save Calculation Results

**Features:** macOS Compatibility

**In-app purchases:** none


### DP

[App page](https://appshunter.io/ios/app/dp-select/id934888136)

This tool helps users configure and select DP pumps for their specific applications. It provides detailed product information, including technical specifications, hydraulic curves, and dimensions, based on your selection criteria.

**Highlights:** Intuitive product configuration, Selection via hydraulic data (Q, H), Replacement product comparison, Direct pump type selection, Technical specification sheets, Hydraulic curves, Dimensions and drawings

**In-app purchases:** none


## Frequently asked questions

### Is Keystone Pump TDH Calculator free?

Keystone Pump TDH Calculator is free to download, with no in-app purchases.

### Is DP free?

DP is free to download, with no in-app purchases.

### Which has better reviews, Keystone Pump TDH Calculator or DP?

Keystone Pump TDH Calculator is rated higher. Keystone Pump TDH Calculator averages 5.0 out of 5 from 1 ratings, while DP averages 4.0 from 1 ratings.

### Do Keystone Pump TDH Calculator or DP have ads?

Neither Keystone Pump TDH Calculator nor DP shows ads.

### Which is updated more often, Keystone Pump TDH Calculator or DP?

Keystone Pump TDH Calculator ships an update every 6 months, and DP every 16 months. Most recently, Keystone Pump TDH Calculator was updated on May 31, 2026 and DP on July 9, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*