Timer 555 Calculator vs 555 Calc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Timer 555 Calculator
Calculate monostable and astable circuits for electronics projects. Determine pulse width and frequency, find component combinations, and save/upload data. Supports multiple languages.
- Monostable circuit pulse width calculation
- Astable circuit frequency calculation
- Component combination finder
- Save component values to CSV
- Upload CSV via AirDrop/iCloud Drive
- Multi-language support
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This app is used to calculate monostable and astable circuit. Features * Calculate pulse width of monostable circuit * Calculate frequency of astable circuit * Find out combination of components making a desire pulse width in monostable circuit * Find out combination of components making a desire frequency in astable circuit * Saving component values in CSV file * Upload generated CSV files via AirDrop or iCloud Drive * Support English, German, French, Italian, Spanish, Portuguese, Japanese, Korean, Russian
555 Calc
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.
- Calculate resistor values
- Input frequency
- Input duty ratio
- Input capacitor value
- Timer IC 555 circuit design
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This App calculates registors value, when designing the circuit using Timer IC 555. How to (1) Input Frequency value. (2) Input Duty Ratio. (3) Input C1 Value. (4) Touch ‘Calculate’ button. (5) Registors value will be displayed. Note. * Set Duty Ratio to 50 ~ 99. * If you set Duty Ratio to 50, R1 value will be set to 0.
Screenshots
Verdict
Timer 555 Calculator and 555 Calc both sit at 3.9 stars, but that hides the real split: 100% of Timer 555 Calculator's written reviews are positive against 50% of 555 Calc's. Timer 555 Calculator also leads on ads (none vs shown) and update cadence (every 3 months vs every 20 months). 555 Calc's advantage is in-app purchases (none vs 1) and iOS requirement (11.0 vs 13.2). On price, rating, ratings volume and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Timer 555 Calculator sells 1 one-off in-app purchase. 555 Calc asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 3.9 for Timer 555 Calculator against 4.0 for 555 Calc. Both are backed by a comparable volume of ratings — 8 and 3 respectively. Written reviews are what separate them: 100% of Timer 555 Calculator's written reviews are positive against 50% of 555 Calc's.
Timer 555 Calculator ships an update every 3 months, 555 Calc every 20 months. The most recent releases landed on September 24, 2026 and June 1, 2026 respectively.
| Parameter | Timer 555 Calculator | 555 Calc |
|---|---|---|
| Price | Free | Free |
| Rating | 3.9 (8 ratings) | 4.0 (3 ratings) — better |
| Positive reviews | 100.0% of reviews — better | 50.0% of reviews |
| Number of ratings | 8 — better | 3 |
| Update frequency | Every 3 months — better | Every 20 months |
| Ads | No — better | Yes |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Ad-supported — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13.2 | 11.0 — better |
| Further details — not scored | ||
| Size | 3 MB | 18 MB |
| Age rating | 4+ | 4+ |
| Developer | Siu Yuen Ho | Jibiki Works |
Customer experience
Timer 555 Calculator
555 Calc
In-app purchases
Timer 555 Calculator
- Unlock Pro feature$0.99
555 Calc
No in-app purchases
Questions
Is Timer 555 Calculator free?
Is 555 Calc free?
Which has better reviews, Timer 555 Calculator or 555 Calc?
Do Timer 555 Calculator or 555 Calc have ads?
Which is updated more often, Timer 555 Calculator or 555 Calc?
Other comparisons
