# 555 Calc vs Coolite

The clearest difference is ads: Coolite at none against 555 Calc's shown. Coolite also leads on update cadence (every 10 days vs every 20 months) and iOS requirement (9.1 vs 11.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

555 Calc ships an update every 20 months, Coolite every 10 days. The most recent releases landed on September 27, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | 555 Calc | Coolite |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (3 ratings)](https://appshunter.io/ios/app/555-calc/id868058244/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 20 months | **Every 10 days** |
| Monetization | Ad-supported | — |
| Size | 18 MB | 44 MB |
| Requires iOS | 11.0 | **9.1** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Jibiki Works](https://appshunter.io/developer/556845808) | [Shenzhen Heaton Technology Co., Ltd.](https://appshunter.io/developer/1076063818) |

## What reviewers say

### 555 Calc

[App page](https://appshunter.io/ios/app/555-calc/id868058244)

This utility app helps engineers and hobbyists calculate resistor values for circuits using the Timer IC 555. Simply input frequency, duty ratio, and capacitor values to get the required resistor outputs.

**Highlights:** Calculate resistor values, Input frequency, Input duty ratio, Input capacitor value, Timer IC 555 circuit design

**Features:** macOS Compatibility

**In-app purchases:** none


### Coolite

[App page](https://appshunter.io/ios/app/coolite/id1532181358)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is 555 Calc free?

555 Calc is free to download, with no in-app purchases.

### Is Coolite free?

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

### Do 555 Calc or Coolite have ads?

555 Calc shows ads; Coolite does not.

### Which is updated more often, 555 Calc or Coolite?

555 Calc ships an update every 20 months, and Coolite every 10 days. Most recently, 555 Calc was updated on September 27, 2026 and Coolite on October 7, 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.*