# Combine Fluids vs ECD Calculator

The clearest difference is price: ECD Calculator at Free against Combine Fluids's $0.99. ECD Calculator also leads on rating (5.0 vs 3.7) and review sentiment (100% vs 67%). Combine Fluids's advantage is in-app purchases (none vs 2) and chart position (#170 vs unranked). On ratings volume, ads and device support there is nothing between them.

ECD Calculator is free to download; Combine Fluids costs $0.99 up front. ECD Calculator sells 2 one-off in-app purchases. Combine Fluids asks for nothing beyond the download.

ECD Calculator holds the better App Store score, 5.0 against 3.7. Both are backed by a comparable volume of ratings — 3 and 5 respectively. Written reviews point the same way: 67% of Combine Fluids's written reviews are positive against 100% of ECD Calculator's.

Combine Fluids ships an update monthly, ECD Calculator every 5 days. The most recent releases landed on October 24, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Combine Fluids | ECD Calculator |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [3.7 (3 ratings)](https://appshunter.io/ios/app/combine-fluids/id1458907903/reviews) | **[5.0 (5 ratings)](https://appshunter.io/ios/app/ecd-calculator/id6754762850/reviews)** |
| Number of ratings | 3 | **5** |
| Positive reviews | 66.7% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 5 days** |
| Monetization | Paid | **Free** |
| Best chart rank | **#170** | — |
| Size | 85 MB | 45 MB |
| Requires iOS | **10.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [GoodStamp](https://appshunter.io/developer/717537129) | [Drillsoft LLC](https://appshunter.io/developer/1787962403) |

## What reviewers say

### Combine Fluids

[App page](https://appshunter.io/ios/app/combine-fluids/id1458907903)

**Currently charting:** #170 Top Paid · Utilities (US App Store)

This utility app helps oil and gas professionals quickly calculate fluid volume combinations. It allows users to input various fluid types and density requirements, saving different mix possibilities for specific wells.

**Highlights:** Combine up to 10 fluid types, Save fluid mix possibilities per well, Calculate volume combinations, Input mud density requirements, Supports volume limitations or not

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### ECD Calculator

[App page](https://appshunter.io/ios/app/ecd-calculator/id6754762850)

This utility app assists drilling and mud engineers in calculating Equivalent Circulating Density (ECD) at any point during operations. It offers a streamlined process with just a few clicks.

**Highlights:** ECD calculation, Drilling engineering, Mud engineering, Point-of-operation calculation, Streamlined interface

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 50 credits | $3.99 | one-time |
| 300 Credits | $9.99 | one-time |


## Frequently asked questions

### Is Combine Fluids free?

Combine Fluids costs $0.99, with no in-app purchases.

### Is ECD Calculator free?

ECD Calculator is free to download, with in-app purchases available.

### Which has better reviews, Combine Fluids or ECD Calculator?

ECD Calculator is rated higher. Combine Fluids averages 3.7 out of 5 from 3 ratings, while ECD Calculator averages 5.0 from 5 ratings.

### Do Combine Fluids or ECD Calculator have ads?

Neither Combine Fluids nor ECD Calculator shows ads.

### Which is updated more often, Combine Fluids or ECD Calculator?

Combine Fluids ships an update monthly, and ECD Calculator every 5 days. Most recently, Combine Fluids was updated on October 24, 2026 and ECD Calculator on October 6, 2026.

---

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