- Voltage Dividers
- Thevenin Equivalent
- Adjustable Resistor Range
- Component of Desired Temperature Coefficient
- LC Resonance: Solve for L, C, R, Freq, Q
- XMEGA USART Baud
- Power Supply Hold-up Time
- Coilcraft SPICE Model Converter
- Convergents (approximations for turns ratios, PLL dividers, etc.)
- Thermistor Data and Functions

Like calculators? Want to see more? Let me know about it.

I don't have so much interest in, say, analyzing and writing filter or impedance calculators. Some things are so simple not to bother with (various resistor divider problems, capacitor/inductor proportions, switching waveforms), or are handled trivially by one of these. Here are my favorites:

- Serge Stroobandt, ON4AA, RF Inductance Calculator for Single-Layer Helical Round-Wire Coils, quite possibly the best damn solenoid inductance/impedance calculator, ever.
- Bob's Electron Bunker, Multi-Layer Coil Inductance Calculator (possibly more accurate than conventional formulas, but still a long way from a capacitance and eddy current-aware calculator; which alas, might never exist for such configurations)
- Chemandy Electronics, Radio Frequency and Microwave JavaScript Calculator Index, covers many typical structures (microstrip, differential stripline, etc.), and other common electronic and RF calculations. (I suspect the numerical accuracy is better than most. Most calculators use the same old piecewise equations, which produces absurd results for parameters outside the approximation range, which is frequently omitted. These calculators solve the Elliptical and Bessel functions as needed!)
- Sourceforge.net, CGI-Wcalc, an impedance calculator toolbox
- OKAWA Electric Design, Filter Design and Analysis (includes 3rd order Sallen-Key and MFB types)
- Jackson Research, Double Tuned Filter, Capacitor Loaded & Capacitor Coupled
- Daycounter, Inc., Electronics Calculators
- MicroModeler, MicroModeler DSP, a web based IDE (non-commercial, limited version)
- Tony Fisher (R.I.P.) at York University, Interactive Digital Filter Design
- Also, LC Filter Design (useful as a design resource, as you can play with values after calculation)
- Texas Instruments (formerly National Semiconductor), SNVA538, Input Filter Design for Switching Power Supplies
- Jansson.us, Resistor Value and Ratio Calculator
- Kirill Kryukov, Resistor Network Finder (even more powerful than Jansson's!)
- Kirill Kryukov, Resistor Network Solver
- Dr. Heinz Schmidt-Walter, et al., Design of Switch Mode Power Supplies
- Lazar Rozenblat, smps.us, PCB Trace Width Calculator and Equations (includes the heat-dissipating effect of ground planes in multilayer construction)
- Lorusso Compliance Services, LLC, IEC 60950 Creepage and Clearance Calculator