Supported Features
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Larger Text
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Dark Interface
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Differentiate Without Colour Alone
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Sufficient Contrast
BenchKit: Electronics Tools
Resistor, trace, drop, divider
Only for iPhone
Free · In-App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Four bench calculations that work offline. Every result shows where its formula stops being valid.
BenchKit puts four everyday electronics calculations in one focused iPhone app. The calculators work offline.
RESISTOR CODES
Decode 3, 4, 5, and 6-band axial resistors by tapping the bands on a drawn resistor, or SMD codes (3-digit, 4-digit, EIA-96, R notation). See the tolerance range, IEC marking code, and standard E-series match. When a reading is probably reversed, one tap flips it.
PCB TRACE WIDTH
Estimate minimum internal or external copper trace width from current, copper weight, and allowed temperature rise, in millimeters or mils, or the current a given width can carry. Results outside the IPC-2221 chart range are flagged as extrapolations.
VOLTAGE DROP
Voltage drop, the drop as a share of the supply, voltage at the load, and power lost in the wiring. Enter the round-trip resistance, or wire gauge (AWG or mm²), length, and conductor temperature.
VOLTAGE DIVIDER
Ideal unloaded output voltage, divider current, per-resistor dissipation, output resistance, and what an optional load does to the output. Or enter a target voltage and get the closest E24/E96 resistor pairs with their worst-case output.
Type values the way engineers write them: 4k7, 2R2, 100m, 3V3; the keyboard has keys for the letters.
Laid out for iPhone Duo: on the open screen the answer and the inputs sit on either side of the fold.
BENCHKIT PRO (optional one-time purchase)
• Value to code: enter a resistance and see its color bands and SMD codes.
• Trace resistance: add a trace length to get its resistance, voltage drop, and heat.
• Wire size for a drop: set an allowed voltage drop and get the thinnest AWG and mm² wire that meets it. Sized for voltage drop only; the wire's current rating is yours to check.
The four tools above are free and stay free.
No account. No ads. No analytics. English, Simplified Chinese, and Japanese.
BenchKit is a quick estimation tool. Always verify production designs against component datasheets, applicable standards, simulation, and physical validation.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
• Ready for iPhone Duo: on the open screen the answer and the inputs sit on either side of the fold.
• Voltage Drop now shows the drop as a share of the supply.
• PCB Trace takes widths in mm or mil.
• A flip button appears when a resistor may have been read from the wrong end.
• Home tiles say what each number is, every tool has a reset, and you can long-press the app icon to jump to a tool.
• New, optional BenchKit Pro (one-time purchase): look up color bands and SMD codes from a value, get a trace's resistance and drop over its length, and find the thinnest wire for an allowed voltage drop. The four tools you already use stay free.
The developer, 明 齐, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
The developer indicated that this app supports the following accessibility features. Learn More
Information
- Provider
- 明 齐
- Size
- 3.7 MB
- Category
- Utilities
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
English and 2 more
- English, Japanese, Simplified Chinese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- BenchKit Pro ฿79.00
- Copyright
- © Ming Qi