# Rx Days’ Supply Calculator vs SRx Affinity

The clearest difference is in-app purchases: SRx Affinity at none against Rx Days’ Supply Calculator's 1. Rx Days’ Supply Calculator's advantage is update cadence (every 4 months vs every 10 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Rx Days’ Supply Calculator sells 1 in-app purchase, starting at $5.99 per year. SRx Affinity asks for nothing beyond the download.

Rx Days’ Supply Calculator ships an update every 4 months, SRx Affinity every 10 months. The most recent releases landed on October 30, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | Rx Days’ Supply Calculator | SRx Affinity |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (7 ratings)](https://appshunter.io/ios/app/rx-days-supply-calculator/id1616890136/reviews)** | — |
| Number of ratings | **7** | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 10 months |
| Monetization | Subscription | — |
| Size | 51 MB | 23 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [PAAS National Technologies LLC](https://appshunter.io/developer/1616890139) | [SUITE RX L L C](https://appshunter.io/developer/1511587832) |

## What reviewers say

### Rx Days’ Supply Calculator

[App page](https://appshunter.io/ios/app/rx-days-supply-calculator/id1616890136)

This app helps community pharmacists and technicians accurately calculate medication days' supply and quantity. It offers specialized calculators for insulin, topical creams, Santyl, and eye drops, minimizing PBM recoupments and aiding recordkeeping.

**Highlights:** Days' supply and quantity calculators, Insulin calculations (all dosage forms, biologics, priming units), Topical creams and ointments (fingertip unit method), Santyl dosing calculator (multiple wounds), Eye drops calculator (solutions, suspensions, PBM specific), PDF generation for recordkeeping, Wireless printing and emailing of results

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Annual Subscription | $5.99 | per year |


### SRx Affinity

[App page](https://appshunter.io/ios/app/srx-affinity/id1624000030)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Rx Days’ Supply Calculator free?

Rx Days’ Supply Calculator is free to download, with in-app purchases available.

### Is SRx Affinity free?

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

### Do Rx Days’ Supply Calculator or SRx Affinity have ads?

Neither Rx Days’ Supply Calculator nor SRx Affinity shows ads.

### Which is updated more often, Rx Days’ Supply Calculator or SRx Affinity?

Rx Days’ Supply Calculator ships an update every 4 months, and SRx Affinity every 10 months. Most recently, Rx Days’ Supply Calculator was updated on October 30, 2026 and SRx Affinity on October 27, 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.*