# Fuel Density Calculation vs K4 Tools

The clearest difference is price: K4 Tools at Free against Fuel Density Calculation's $2.99. K4 Tools also leads on update cadence (monthly vs every 2 months). On rating, ratings volume, ads and in-app purchases there is nothing between them.

K4 Tools is free to download; Fuel Density Calculation costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for Fuel Density Calculation against 5.0 for K4 Tools. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

Fuel Density Calculation ships an update every 2 months, K4 Tools monthly. The most recent releases landed on August 22, 2026 and July 3, 2026 respectively.

## The numbers

| Metric | Fuel Density Calculation | K4 Tools |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [5.0 (2 ratings)](https://appshunter.io/ios/app/fuel-density-calculation/id6636469810/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/k4-tools/id6758374210/reviews) |
| Number of ratings | **2** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Monthly** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 31 MB |
| Requires iOS | **17.0** | 17.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Richard Montoya](https://appshunter.io/developer/1762752434) | [James Everett](https://appshunter.io/developer/1015137244) |

## What reviewers say

### Fuel Density Calculation

[App page](https://appshunter.io/ios/app/fuel-density-calculation/id6636469810)

This utility app assists wide-body aircrews, specifically for Boeing and Airbus aircraft, in comparing uploaded fuel quantities with actual fuel on board. It incorporates density calculations for accurate fuel management.

**Highlights:** Fuel density calculations, Compare uploaded vs. actual fuel, Designed for Boeing and Airbus aircrews, Accurate fuel on board (FOB) verification

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

**In-app purchases:** none


### K4 Tools

[App page](https://appshunter.io/ios/app/k4-tools/id6758374210)

This app assists flight crews with inflight fuel and time calculations, integrating with flight plans. Features include scanning flight data, calculating duty and rest periods, and managing crew breaks. It also helps verify fuel accuracy and pre-flight weather conditions.

**Highlights:** Magic Scanner for FMS data, Duty/Rest period calculation, Crew break scheduling, Fuel receipt verification, Pre-flight weather checks, iPad optimized interface

**In-app purchases:** none


## Frequently asked questions

### Is Fuel Density Calculation free?

Fuel Density Calculation costs $2.99, with no in-app purchases.

### Is K4 Tools free?

K4 Tools is free to download, with no in-app purchases.

### Which has better reviews, Fuel Density Calculation or K4 Tools?

Fuel Density Calculation and K4 Tools are both rated 5.0 out of 5 on the App Store, from 2 and 1 ratings respectively.

### Do Fuel Density Calculation or K4 Tools have ads?

Neither Fuel Density Calculation nor K4 Tools shows ads.

### Which is updated more often, Fuel Density Calculation or K4 Tools?

Fuel Density Calculation ships an update every 2 months, and K4 Tools monthly. Most recently, Fuel Density Calculation was updated on August 22, 2026 and K4 Tools on July 3, 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.*