Online Calculators
From everyday calculators like percentages and dates to electronics calculators for resistors and voltage dividers: the math happens right in your browser.
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All tools in this category
Battery & EV Charge Time Calculator
Calculate charge time, finish time, and costs for EVs and batteries - with charge curve and live tracking.
Calendar Week Calculator
Show current calendar week (CW) and convert date to calendar week.
Capacitor Charge Time Calculator
Calculate the RC time constant and charge/discharge curve of a capacitor through a resistor, including voltage over time, time to reach a target level, and a visual curve.
Company Car & Leasing Calculator
Calculate benefit-in-kind (1%, 0.5% & 0.25% rule), net salary impact, lease factor, and savings compared to private purchase.
Cron-Job Visualizer
Create Cron jobs interactively and visualize execution times on a calendar and timeline.
Date Calculator
Calculate the duration between two dates or add/subtract days from a date.
I²C Pull-up & UART Baud Rate Calculator
Calculate I²C pull-up resistors from bus capacitance and speed, or find the UART baud rate error for a given MCU clock frequency (ESP32, Arduino, STM32).
Percentage Calculator
Calculates percentage value, rate, percentage change, discount with cash discount, VAT, and tip splitting.
Pomodoro Timer
A simple Pomodoro timer for productivity and regular breaks.
Resistor Calculator (Color Code & SMD)
Calculate resistance values interactively from 4, 5, and 6 band color codes, convert values back to color codes, or decode SMD markings (3-digit, 4-digit & EIA-96).
Stopwatch
Precise stopwatch with lap times.
Timezone Planner
Find ideal meeting times and plan global appointments by overlapping multiple timezones.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa.
Voltage Divider Calculator
Calculate output voltage, quiescent current, and power dissipation of voltage dividers or automatically find the best E12/E24/E96 resistor pairs for your target voltage.