# Combine Fluids vs DrillOut Calcs

The clearest difference is price: DrillOut Calcs at Free against Combine Fluids's $0.99. DrillOut Calcs also leads on rating (5.0 vs 3.7) and review sentiment (100% vs 67%). Combine Fluids's advantage is iOS requirement (10.0 vs 18.5). On ratings volume, update cadence, ads and in-app purchases there is nothing between them.

DrillOut Calcs is free to download; Combine Fluids costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

DrillOut Calcs holds the better App Store score, 5.0 against 3.7. Both are backed by a comparable volume of ratings — 3 and 2 respectively. Written reviews point the same way: 67% of Combine Fluids's written reviews are positive against 100% of DrillOut Calcs's.

Combine Fluids ships an update monthly, DrillOut Calcs every 3 weeks. The most recent releases landed on November 6, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | Combine Fluids | DrillOut Calcs |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [3.7 (3 ratings)](https://appshunter.io/ios/app/combine-fluids/id1458907903/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/drillout-calcs/id6754534235/reviews)** |
| Number of ratings | **3** | 2 |
| Positive reviews | 66.7% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | **Every 3 weeks** |
| Monetization | Paid | **Free** |
| Size | 85 MB | 3 MB |
| Requires iOS | **10.0** | 18.5 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [GoodStamp](https://appshunter.io/developer/717537129) | [Cody Martin](https://appshunter.io/developer/1796736420) |

## What reviewers say

### Combine Fluids

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

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


### DrillOut Calcs

[App page](https://appshunter.io/ios/app/drillout-calcs/id6754534235)

This app offers essential calculations for oilfield professionals performing post-frac plug drill-outs. It provides quick and accurate tools to verify flow balance, annular velocity, sweep efficiency, and surface return timing in real time, designed for simplicity and speed.

**Highlights:** Post-frac plug drill-out calculations, Flow balance verification, Annular velocity calculation, Sweep efficiency assessment, Surface return timing, Real-time data verification

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

**In-app purchases:** none


## Frequently asked questions

### Is Combine Fluids free?

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

### Is DrillOut Calcs free?

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

### Which has better reviews, Combine Fluids or DrillOut Calcs?

DrillOut Calcs is rated higher. Combine Fluids averages 3.7 out of 5 from 3 ratings, while DrillOut Calcs averages 5.0 from 2 ratings.

### Do Combine Fluids or DrillOut Calcs have ads?

Neither Combine Fluids nor DrillOut Calcs shows ads.

### Which is updated more often, Combine Fluids or DrillOut Calcs?

Combine Fluids ships an update monthly, and DrillOut Calcs every 3 weeks. Most recently, Combine Fluids was updated on November 6, 2026 and DrillOut Calcs on November 5, 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.*