BasicATTCalc vs iSmith
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
BasicATTCalc
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Basic Attenuator Calculator (BasicATTCalc) helps you calculate various resistive attenuators which are used in many audio, video and RF circuit design applications. The standard resistance values based on E-series numbers are outputted in inputting necessary conditions such as source impedance, load impedance and attenuation. Features The calculable attenuators and impedance converters are as follows: - Type T - Type Pi (π) - Type H - Type O - Type Bridged T - Type Bridged H - Type L (Impedance converter) - Type U (Impedance converter) Calculated resistance values are displayed with ideal values or the following E-series number specified either. E12, E24, E48, E96, E192 The most suitable values are calculated in selecting priority calculation whether Simple or Precision. - Simple: Perform calculations that the nearest values are derived to desired impedances and attenuation by the simple structure - Precision: Perform calculations that the nearest values are derived to desired impedances and attenuation by consisting of up to 4 resistors per an element In addition to resistance values, this application provides you with input impedance, output impedance and calculated attenuation with mismatch loss. If necessary, it is able to calculate power dissipated by each resistor and parameters such as reflection coefficient, VSWR, return loss and mismatch loss. Attention Because the standard resistors are used, the following restriction is set up. - Range of resistance value: 1Ω ~ 10MΩ (except ideal values)
iSmith
This app helps users understand impedance matching principles. It allows for reading key network parameters from a Smith chart and calculating various matching networks and pads. Users can also convert between different power and voltage units.
- Read Smith chart parameters (Z, Y, VSWR, Q, Gamma)
- Calculate 8 L-matching networks
- Calculate T & Pi matching pads
- Set matching targets on Smith chart
- Learn impedance matching principles
- dBm, Watts, and Volts conversion
- VSWR conversion
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Features: - Read out Z, Y, VSWR, Q and Gamma from smith chart. - Calculate 8 L-matching networks. - Set matching target by touching smith chart. - Calculate T & Pi matching pad. - Learn the principle of impedance matching. - dBm, Watts and Volts conversion - VSWR Conversion
Screenshots
Verdict
The clearest difference is price: iSmith at Free against BasicATTCalc's $1.99. iSmith also leads on update cadence (every 2 days vs every 29 months). BasicATTCalc's advantage is ads (none vs shown) and iOS requirement (14.5 vs 16.0). On in-app purchases 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
iSmith is free to download; BasicATTCalc costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
BasicATTCalc ships an update every 29 months, iSmith every 2 days. The most recent releases landed on September 20, 2026 and June 6, 2026 respectively.
| Parameter | BasicATTCalc | iSmith |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | — | 5.0 (1 ratings) — better |
| Number of ratings | — | 1 — better |
| Update frequency | Every 29 months | Every 2 days — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | — | Ad-supported |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 14.5 — better | 16.0 |
| Further details — not scored | ||
| Size | 7 MB | 7 MB |
| Age rating | 4+ | 4+ |
| Developer | TAKAHIKO FUKUYAMA | Ryoun Chon Shin |
In-app purchases
BasicATTCalc
No in-app purchases
iSmith
No in-app purchases








