⚙

EmbedCalc

Essential calculators for embedded & electronics engineers.
Real-time results. No account. No bloat.

📐

PWM / Timer

Frequency, period, duty cycle

📡

UART Baud Rate

Error rate, PASS/FAIL check

📊

ADC Resolution

LSB voltage, SNR, dynamic range

🐕

Watchdog Timer

STM32 IWDG & WWDG timeouts

🎛

I2C Timing

Bus timing & pull-up values

🔲

Bit Field Visualizer

32-bit register breakdown

🔢

Q-Format Converter

Float ↔ fixed-point

🧮

Number Base Converter

Dec, Hex, Bin, Oct converter

⚡

Ohm's Law

V, I, R, P — any 2 → all 4

➗

Voltage Divider

Vout, loaded divider, Thevenin

💡

LED Resistor

Series/parallel configs & E24

🎨

Resistor Code

Color bands & SMD decoder

🔺

Op-Amp Gain

Amp configurations & Schmitt

➰

LC Resonance

LCR resonant freq, Q-factor

🔀

BJT Bias CE

Q-point & stability factor

〰

RC Filter

Cutoff frequency, gain & phase

⏱

NE555 Timer

Astable / monostable

🔋

Capacitor Charge

RC time constant, τ milestones

🔊

dB Converter

dB, dBm & mW bidirectional

🔋

Battery Life

Estimated system run-time

📉

Buck / Boost

Switching regulator design

🌡

Temperature

Units & RTD sensor temps

🔄

CRC Calculator

CRC-8/16/32, 7 polynomials

🔄

Checksum / CRC

XOR, Sum8/16, LRC, CRC

📐

PWM / Timer Calculator

Calculate PWM frequency, period, and duty cycle from MCU timer settings.

Quick Presets

Input Parameters

MCU Timer Clock MHz

STM32 APB Prescaler != 1 (Timer clk = 2x APB)

Counter Mode

Prescaler (PSC) 0–65535

Auto-Reload Register (ARR) 0–65535

Duty Cycle %

Dead Time Count DTG [0-255]

ℹ Edge: f = CLK / (PSC+1) / (ARR+1) | Center: f = CLK / (PSC+1) / (2 * (ARR+1))

Results

Timer Clock—

PWM Frequency—

Period—

Duty Resolution—

Duty Steps—

CCR Value (for duty%)—

Dead Time Duration—

Min Achievable Freq—

Max Achievable Freq—

📡

UART Baud Rate Calculator

Calculate actual baud rate and error percentage from MCU system clock.

Common Baud Rates

Input Parameters

System Clock MHz

Target Baud Rate bps

Oversampling

Data Bits

Parity

Stop Bits

ℹ Error ≤ 0.5% = excellent, ≤ 2% = acceptable, > 2% = unreliable

Results

Status—

USART_DIV (exact)—

USART_DIV (rounded)—

STM32 BRR Value—

Actual Baud Rate—

Error Rate—

Bit Time (1 baud)—

Frame Time—

Frame Size—

Standard Baud Rates Error Table (at current Clock)

Baud Rate	Actual	Error	Status

📊

ADC Resolution Calculator

Calculate LSB voltage, SNR, dynamic range, and timing specifications for ADC configurations.

Input Parameters

ADC Resolution bits

Reference Voltage (Vref) V

ADC Clock MHz

Sampling Cycles (STM32)

Hardware Oversampling Ratio

Channels in Scan Sequence

Quick Select

Results

Total Steps—

LSB Voltage—

Full Scale—

Theoretical SNR—

Dynamic Range—

ENOB—

Single Conv Time—

Max Sample Rate—

Effective Resolution—

Total Scan Time—

Comparison Table

Resolution	LSB @ Vref	SNR

🔲

Bit Field Register Visualizer

Enter a 32-bit hex value to visualize individual bits. Click any bit to toggle it.

Hex Input

32-bit Visualization (click to toggle)

Decoded Values

Decimal—

Hex—

Set Bits—

Binary

—

🔢

Fixed Point (Q-Format) Converter

Convert between floating-point and signed Qm.n fixed-point representation.

Input

Integer bits (m)

Fractional bits (n)

Float value → Q integer

Q integer → Float (reverse)

Results

Format—

Valid Range—

Scale Factor (2^n)—

Q Integer—

Hex—

Binary—

Actual value—

Quantization Error—

⚡

Ohm's Law Calculator

Enter any 2 of V, I, R to calculate all 4 values including power (P).

Input (any 2)

Voltage (V) V

Current (I) A

Resistance (R) Ω

ℹ Enter any 2 values to calculate the third.

Results

Voltage (V)—

Current (I)—

Resistance (R)—

Power (P = V×I)—

➗

Voltage Divider Calculator

Calculate output voltage, current, and power for a resistive voltage divider (loaded or unloaded).

Input Parameters

Input Voltage (Vin) V

R1 (top) Ω

R2 (bottom) Ω

Load Resistance (Rload) Ω (optional)

ℹ Vout = Vin × R2_eff / (R1 + R2_eff) | R2_eff = R2 || Rload

Results

Output Voltage (unloaded)—

Output Voltage (loaded)—

Loading Error %—

Current—

Power Dissipation—

Voltage Ratio—

Total Resistance—

Thevenin Equivalent—

💡

LED Current Limiting Resistor

Find the nearest E24 standard resistor value and power rating to safely drive your LEDs.

Input Parameters

LED Color Preset

Supply Voltage (Vs) V

LED Forward Voltage (Vf) V

Desired LED Current (If) mA

Configuration

LED Count

ℹ Series: R = (Vs − (n × Vf)) / If | Parallel: R = (Vs − Vf) / (n × If)

Results

Total LED Voltage Drop—

Voltage across R—

Exact Resistance—

★ E24 Standard Value—

Actual Current (with E24)—

Power Dissipation—

Recommended Resistor Rating—

🎨

Resistor Code & Band Calculator

Decode 4/5-band color codes, reverse lookup values to colors, and decode SMD resistor markings.

Color Bands (Bands → Value)

Number of Bands

Results

Resistance Value—

Tolerance—

Min Value—

Max Value—

Reverse Lookup (Value → Bands)

Resistance Value Ω

Calculated Color Bands

Enter ohm value above

Nearest Standard E24 Value—

SMD Resistor Code Decoder

SMD Marking Code

Decoded Resistance—

ℹ Supports: 3-digit, 4-digit, R-style, and EIA-96 codes.

🔺

Op-Amp Gain & Bandwidth Calculator

Calculate voltage gain, bandwidth, slew rate limits, and Schmitt trigger thresholds.

Configuration

Amplifier / Comparator Type

Rin (Input Resistor) Ω

Rf (Feedback Resistor) Ω

Gain-Bandwidth Product (GBW) MHz

Slew Rate V/µs

Output Swing (Vpp) V

Results

Voltage Gain / Mode—

Gain (dB)—

Phase—

Formula / Trip values—

Bandwidth (-3dB)—

Max Sine Freq (Slew Rate limited)—

Upper Trip Point (Vut)—

Lower Trip Point (Vlt)—

Hysteresis (Vhys)—

〰

RC Filter Calculator

Calculate cutoff frequency, time constant, impedance, and gain/phase characteristics for first-order filters.

Input Parameters

Resistance Ω

Capacitance

Filter Type

Test Frequency Hz

Results

Filter Type—

Time Constant (τ = RC)—

Cutoff Frequency (fc)—

Angular Frequency (ωc)—

Attenuation slope—

-20 dB point—

Gain at Test Freq—

Phase at Test Freq—

Impedance (Z) at Test Freq—

Frequency Response Table

Decade	Frequency	Gain (dB)	Phase Shift

⏱

NE555 Timer Calculator

Calculate frequency, duty cycle, and timing for astable and monostable 555 configurations.

Configuration

Mode

Ra Ω

Rb Ω

Capacitor C

Results

Time HIGH—

Time LOW—

Period—

Frequency—

Duty Cycle—

🔋

Capacitor Charge / Discharge

Calculate RC time constant and voltage milestones during capacitor charging/discharging.

Input Parameters

Resistance (R) Ω

Capacitance (C)

Supply Voltage (Vs) V

Initial Voltage (V0) V

Results

Time Constant (τ = RC)—

1τ (63.2%)—

2τ (86.5%)—

3τ (95.0%)—

5τ (99.3% ≈ full)—

Stored Energy—

Charge (Q = C×V)—

🔄

CRC Calculator

Compute CRC checksums for 7 common polynomials simultaneously.

Input Data

0 bytes

Results

🐕

Watchdog Timer Calculator

Calculate timeout and window constraints for STM32 IWDG and WWDG.

Input Parameters

Watchdog Type

LSI Clock Hz

Prescaler (PR)

Reload Value (RLR) 0–4095

Results

Calculated Timeout—

Min Timeout (RLR=0 / T=64)—

Max Timeout (RLR=4095 / T=127)—

Refresh Window Time Range—

🎛

I2C Timing & Pull-Up Resistor

Calculate bus timing requirements, pull-up resistor limits, and STM32 TIMINGR values.

Input Parameters

Speed Mode

Bus Voltage (Vdd) V

Bus Capacitance (Cb) pF

STM32 I2C Clock (I2CCLK) MHz

Results

SCL Period—

SCL High Time (tHIGH)—

SCL Low Time (tLOW)—

Rise/Fall Time Limits—

Min Pull-Up (Rp min)—

Max Pull-Up (Rp max)—

STM32 TIMINGR Value—

STM32 PRESC / SCLH / SCLLPresc: — | H: — | L: —

🧮

Number Base Converter

Simultaneous conversion between Decimal, Hexadecimal, Binary, and Octal formats (unsigned 32-bit).

Input Fields (all editable)

Decimal (Signed/Unsigned)

Hexadecimal

Binary

Octal

Analysis

Set Bits (Ones Count)—

Unsigned 32-bit Dec—

➰

LC Resonance Calculator

Calculate resonant frequency, angular frequency, Q-factor, and bandwidth for series or parallel LC/LCR circuits.

Input Parameters

Inductance (L)

Capacitance (C)

Circuit Config

Resistance (R) Ω

Results

Resonant Frequency (f0)—

Angular Frequency (ω0)—

Characteristic Impedance (Z0)—

Quality Factor (Q)—

Bandwidth (BW)—

Damping Ratio (ζ)—

🔀

BJT CE Bias Divider Network

Calculate voltages, collector current, operating Q-point, and stability factor for a common-emitter bias network.

Input Parameters

Supply Voltage (Vcc) V

R1 (top base) Ω

R2 (bottom base) Ω

Rc (collector) Ω

Re (emitter) Ω

Current Gain (β / hFE)

Results

Base Voltage (Vb)—

Collector Voltage (Vc)—

Collector Current (Ic)—

Collector-Emitter Voltage (Vce)—

Operating point (Q-point)—

BJT Bias State—

🔊

dB & dBm Converter

Calculate decibel ratios (power/voltage) and absolute power in dBm and mW (bidirectional).

Relative dB (Ratio)

dB Mode

dB Value

Ratio (Value2 / Value1)

Absolute Power (dBm / mW)

Power (dBm)

Power (mW)

Power in dBW—

🔋

Battery Life Calculator

Calculate estimated battery run-time based on current draw, system efficiency, and battery count.

Input Parameters

Battery Preset

Battery Capacity (single) mAh

Load Current mA

Regulator / Circuit Efficiency %

Batteries in Parallel

Self-Discharge Rate % / month

Results

Calculated Runtime—

Runtime in Days—

Runtime at 80% Capacity—

Self-Discharge (after 6 mo)—

📉

Buck / Boost / Buck-Boost Calculator

Calculate inductor and capacitor requirements for switching regulators.

Input Parameters

Regulator Type

Input Voltage (Vin) V

Output Voltage (Vout) V

Max Output Current (Iout) A

Switching Freq kHz

Inductor Ripple Current %

Allowed Output Ripple Voltage mV

Results

Duty Cycle (D)—

Min Inductance (L min)—

Min Output Capacitance (C min)—

Estimated Input Current—

Diode/Switch Peak Current—

🌡

Temperature & Sensors Calculator

Convert temperature units and calculate resistance-to-temperature mapping for NTC and PT100 sensors.

Unit Converter (all editable)

Celsius (°C)

Fahrenheit (°F)

Kelvin (K)

Rankine (°R)

NTC Thermistor / PT100 RTD

NTC Preset

NTC R25 (25°C) Ω

NTC B-coefficient

NTC Measured Resistance Ω

NTC Temp Output—

PT100 Measured Resistance Ω

PT100 Temp Output—

🔄

Checksum & CRC Calculator

Calculate XOR, Sum8/16, Two's complement, LRC, and CRC-8/16/32 from ASCII text or Hex bytes.

Input Data

Standard Checksums

XOR Checksum—

Sum 8-bit—

Sum 16-bit—

Two's Complement—

LRC Checksum—

CRC Algorithms

CRC-8 (SMBus)—

CRC-16 (Modbus)—

CRC-32 (Ethernet)—