# 3D Interpolation vs ECD Calculator

The clearest difference is review sentiment: ECD Calculator at 100% against 3D Interpolation's 0%. ECD Calculator also leads on price (Free vs $9.99) and update cadence (every 5 days vs every 37 months). 3D Interpolation's advantage is in-app purchases (none vs 2) and iOS requirement (12.0 vs 15.1). On ads and device support there is nothing between them.

ECD Calculator is free to download; 3D Interpolation costs $9.99 up front. ECD Calculator sells 2 one-off in-app purchases. 3D Interpolation asks for nothing beyond the download.

3D Interpolation ships an update every 37 months, ECD Calculator every 5 days. The most recent releases landed on November 1, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | 3D Interpolation | ECD Calculator |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | — | **[5.0 (5 ratings)](https://appshunter.io/ios/app/ecd-calculator/id6754762850/reviews)** |
| Number of ratings | — | **5** |
| Positive reviews | 0.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 37 months | **Every 5 days** |
| Monetization | Paid | **Free** |
| Size | 7 MB | 45 MB |
| Requires iOS | **12.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Carlos Moura](https://appshunter.io/developer/407501202) | [Drillsoft LLC](https://appshunter.io/developer/1787962403) |

## What reviewers say

### 3D Interpolation

[App page](https://appshunter.io/ios/app/3d-interpolation/id1000298349)

Calculate key directional drilling parameters like TVD, coordinates, and displacement. This tool aids drilling engineers and students in oil well directional drilling by interpolating survey data.

**Highlights:** Calculate TVD, N/S, E/W coordinates, Determine Horizontal Displacement, Calculate Dog-Leg Severity, Measure Build-Up Rate, Calculate Turn Rate, Interpolate parameters between survey stations

**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 3D Interpolation free?

3D Interpolation costs $9.99, with no in-app purchases.

### Is ECD Calculator free?

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

### Do 3D Interpolation or ECD Calculator have ads?

Neither 3D Interpolation nor ECD Calculator shows ads.

### Which is updated more often, 3D Interpolation or ECD Calculator?

3D Interpolation ships an update every 37 months, and ECD Calculator every 5 days. Most recently, 3D Interpolation was updated on November 1, 2026 and ECD Calculator on October 30, 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.*