Tag: guide

Build practical 555 timer circuits in astable and monostable modes. Includes formulas, component selection, and a free online calculator.

Decode ceramic capacitor markings instantly. Learn the 3-digit code system, common values, and how capacitance relates to frequency filtering.

Calculate the correct current-limiting resistor for any LED. Covers forward voltage, standard resistor values, and common mistakes.

Convert cups to grams, scale recipes up or down, and convert oven temperatures between Celsius, Fahrenheit, and Gas Mark.

Generate color palettes, calculate aspect ratios, check screen DPI, and create favicons — free design tools that run in your browser.

JSON formatting, regex testing, JWT decoding, subnet calculation, and more — a walkthrough of the raatools developer toolkit.

Plan your budget, calculate loan payments, convert salaries, estimate taxes, and figure out take-home pay with these free finance tools.

Check your IP, inspect DNS records, look up domain registration, verify SSL certificates, and analyze HTTP headers — free internet diagnostic tools.

Seven simple math tools for everyday calculations — percentages, fractions, GPA, tips, age, Roman numerals, and number-to-words.

Master Ohm's Law and the power formula with practical examples. Calculate voltage, current, resistance, and wattage for any circuit.

Learn PCB trace width sizing with the IPC-2221 standard. Covers current capacity, temperature rise, copper weight, and a free trace width calculator.

Learn how to read 4-band and 5-band resistor color codes. Free chart and interactive decoder tool — no guessing required.

Generate meta tags, preview Open Graph cards, check Google SERP appearance, build robots.txt files, and analyze keyword density — free SEO tools.

Decode SMD resistor markings instantly. Covers 3-digit, 4-digit, R-notation, and EIA-96 code systems with examples and a free decoder tool.

Convert time zones, calculate date differences, set countdowns, and do time math — free browser-based time tools.

Understand voltage dividers with practical examples. Learn the formula, when to use them, and common pitfalls with loaded outputs.

Calculate your basal metabolic rate and daily calorie needs with the Mifflin-St Jeor equation. Includes macro split.

Paste a DNA or RNA sequence and get the complementary strand, mRNA, and protein translation with color-coded codons.

Click any element to see its full electron configuration, noble gas shorthand, and orbital filling diagram.

Struggling with balancing chemical equations? This tool shows you the balanced result and explains each step.

Enter three of the five SUVAT variables and instantly get the other two. Shows which equation was used.

Need a quick molar mass lookup? Type any formula and get the molecular weight plus element breakdown instantly.

Find the moon phase, illumination percentage and lunar age for any date. Includes a 14-day forecast strip.

Calculate voltage, current and resistance with Ohm's Law. Plus decode 4-band and 5-band resistor color codes.

Convert between pH, pOH and ion concentrations instantly. Includes a visual scale with common substances.

Compare planets side by side — gravity, size, day length — and calculate what you'd weigh on Mars, Jupiter or any world.

Launch a projectile with custom angle, speed and gravity. See the trajectory, max height, range and flight time.

Generate Punnett squares for monohybrid and dihybrid crosses. See genotype and phenotype ratios instantly.

Pick an isotope, set the initial mass, and watch exponential decay unfold on an interactive SVG chart.

Visualize the solar system with accurate relative distances or sizes. Zoom, pan, and switch between distance and size modes.

Solve dilution problems instantly. Enter three values and the calculator finds the fourth — supports M, mM, µM, mL, µL.

Interactive ray diagram for converging and diverging lenses. Drag the object to see how the image changes in real time.

Adjust amplitude, frequency and phase of two waves and watch constructive and destructive interference in real time.

Math isn't just for exams — it's how you check your paycheck, compare deals, and avoid getting ripped off. Here's where you'll actually use it.

Translate text to Morse code, Braille, or the NATO phonetic alphabet — fun tools with real-world uses.

Convert anything — units, temperatures, currencies, colors, and even text to QR codes. All free, all in your browser.

Look up GSM providers by MCC/MNC codes — handy for telecom work and international travel.

A practical guide to the raatools image tools — compress, resize, convert, and crop images right in your browser.

Learn how to merge, split, and compress PDFs plus encode files with Base64 — all in your browser, no uploads needed.

Check your BMI, generate random ages, or test your typing speed — a few handy tools that didn't fit anywhere else.

Tools for radio enthusiasts and network nerds — look up MAC addresses, Bluetooth vendors, and calculate antenna frequencies.

Count words, change case, remove duplicates, generate placeholder text, and preview Markdown — five text tools that save you time.