Free guides

Plain, step-by-step answers to everyday file and number questions: how to get a photo under 50 KB, merge PDFs, convert HEIC or work out an EMI. Each one ends with a free tool that does the job in your browser.

Calculators guides

• Metric to Imperial Conversions Chart (Free Converter)Metric to imperial conversions in one chart: cm to inches, kg to lb, km to miles, litres to gallons, °C to °F. Exact factors and a free converter.
• No Cost EMI Explained: Hidden GST and Fees (Free Check)No cost EMI means a discount cancels the interest, but you still pay GST on that interest and often a processing fee. See the maths and check it for free.
• Pay Off Student Loans Faster: Extra Payment Maths (Free)An extra $100 a month on a $30,000 student loan at 6.5% clears it almost 3 years early and saves about $3,350. Run your own payoff numbers free.
• Personal Loan EMI Calculator: Fees and True Cost (Free)Work out a personal loan EMI with the free EMI calculator, then add processing fees and GST to see the total cost and why the effective rate is higher.
• The Pomodoro Technique: How It Works (Free Focus Timer)The Pomodoro Technique splits work into 25-minute focus rounds with short breaks and a longer break after four. How to do it well, with a free focus timer.
• PPF Calculator: How to Calculate PPF Maturity (Free)₹1.5 lakh a year in PPF for 15 years at 7.1% grows to about ₹40.68 lakh. See the formula, the 5th-of-the-month rule, and how to estimate with a free calculator.
• PPF vs FD: Returns, Tax, Lock-in and Liquidity ComparedPPF pays tax-free interest but locks money for 15 years; FDs are flexible but taxed at your slab. See a 15-year comparison and which suits which goal.
• Margin vs Markup: Formulas and Examples (Free)Markup is profit ÷ cost; margin is profit ÷ selling price. Buy at 100, sell at 150: 50% markup, 33.33% margin. Formulas, chart, free percentage calculator.
• How to Read and Write Roman Numerals (Free Converter)Roman numerals use seven letters that add up, with a smaller letter before a larger one subtracted. Learn the rules, see a chart, and use a free converter.
• Repeating Decimal to Fraction: Step by Step (Free)Turn 0.333... into 1/3 and 0.1666... into 1/6 with a simple algebra trick, learn the 9s shortcut, and check your answer with a free converter.
• Roman Numeral Dates for Tattoos and Weddings (Free)Write a wedding or birth date in Roman numerals: convert day, month and year separately, choose an order and separator, and check the spelling with a free tool.
• Rubik's Cube Timer: Time Solves and Work Out Ao5 (Free)Time Rubik's cube solves with a free online stopwatch, work out your average of 5 (ao5) the competition way, and practise the 15-second inspection rule.
• Rule of 72: How Long to Double Money (Free Calculator)Divide 72 by the yearly interest rate to estimate the years to double your money. See how accurate it is at each rate and check it with a free calculator.
• How to Schedule Meetings Across Time Zones (Free)Find a meeting time that works in several cities, avoid daylight saving mix-ups and share times clearly, with a free time zone converter and planner.
• Set a Timer for 10 Minutes: Free Online 10-Minute TimerPress the 10 min button and the free countdown timer starts at once, with a chime at zero. Ideas for 10-minute tidy-ups, breaks and talks.
• 5 Minute Timer: Free Online Timer with a ChimeA free 5 minute timer: press Start (it's already set to 5) or the 5 min button, and a chime plays at zero. Uses for tea, planks and exam practice.
• SGPA vs CGPA: Difference and CGPA Formula (Free)SGPA is your average for one semester; CGPA averages all semesters, weighted by credits. Formulas, a worked example and free percentage checks.
• Simple Interest vs Compound Interest: Formulas and UsesSimple interest is charged only on the original amount; compound interest also earns on past interest. Both formulas, worked examples and a free calculator.
• SIP vs FD: Risk, Returns and Which Fits Your GoalAn FD gives a guaranteed rate; an equity SIP can earn more over long periods but can also fall. Compare 10-year outcomes and tax with a free calculator.
• How to Split the Bill With Tip and Tax (Free Calculator)Split a restaurant bill evenly with tip and tax, round shares to whole amounts, or split by what each person ordered, with a free tip calculator.
• Time Blocking: Plan Your Day in Blocks (Free Timer)Time blocking means giving every part of your day a job in advance. How to plan blocks, size them realistically and use a free timer to stick to them.
• Lap Timer: How to Time Laps With a Free StopwatchPress Lap at the end of each lap to record lap and total times for running, swimming or circuits. Lap vs split, plus shortcuts, in a free online stopwatch.
• USD to INR: Free Converter and What Moves the RateConvert US dollars to Indian rupees with the free currency converter, updated every working day, and learn why the rate moves and why banks pay less.
• UTC vs GMT: What's the Difference? (Free Converter)UTC is the world time standard, kept by atomic clocks. GMT is a UK winter time zone. Same time, but London isn't on GMT all year. Free time zone converter.
• What Date Is 90 Days From Today? Free Day CounterFind the date 90 days from today, or from any date, with the free date calculator, and learn when to count the first day for warranties, returns and visas.
• What Week Number Is It? ISO Week Rules Explained (Free)See today's week number and understand ISO 8601 week rules: weeks start Monday, and week 1 holds the year's first Thursday. Free week number calculator.
• How to Write in Scientific Notation (Free Converter)Move the decimal until one non-zero digit is left of it, then count the moves as the power of ten. Examples, E notation, free scientific notation converter.

Everyday apps guides

• Best Bill Splitting Apps Compared: Which One Suits You?Splitwise, Tricount, Settle Up, Splid and Expense Split compared: how each splits shared costs, what each does best and who each one suits.
• Best Budget Apps Compared: Which One Suits You?YNAB, Monarch Money, Goodbudget, EveryDollar and a free Budget & Expense Tracker compared: how each plans your month, and who each one suits.
• Best Dictionary Apps Compared: Which One Suits You?Merriam-Webster, Dictionary.com, Oxford Learner's, Apple Dictionary, WordReference and our Dictionary compared: what each does best and who it suits.
• Best Expense Tracker Apps Compared: Which Suits You?The main expense tracker apps compared: Monefy, Spendee, Wallet, Money Manager and our free Budget & Expense Tracker, and who each one suits.
• Best Flashcard Apps Compared: Which One Suits You?Anki, Quizlet, Brainscape, RemNote, Memrise and our free Flashcards app compared: what each is for and who it suits.
• Best Language Learning Apps Compared: Which Suits You?Duolingo, Babbel, Busuu, Memrise, Pimsleur and Learn Language compared: what each is built for, who it suits, and how to choose the right one.
• Best Medication Reminder Apps Compared: Which Suits You?Medisafe, MyTherapy, Apple Health, Samsung Health and a free Medication Reminder compared: what each does well, and who each one suits.
• Best Mood Tracker Apps Compared: Which One Suits You?Daylio, Bearable, How We Feel, Apple Health and a free Mood Tracker compared: what each does well, and who each one suits.
• Best Notes Apps Compared: Which One Suits You?Google Keep, Apple Notes, OneNote, Evernote, Notion, Obsidian and our free Notes app compared: what each is for and who it suits best.
• Best Recipe Keeper Apps Compared: Which One Suits You?Paprika, Samsung Food, AnyList, Plan to Eat, Copy Me That and our free Recipe Keeper compared: what each is for and who it suits.
• Best Translator Apps Compared: Which One Suits You?Google Translate, DeepL, Apple Translate, Reverso and our Translator compared: what each does best, where it works and who it suits.
• Best Weight Tracker Apps Compared: Which One Suits You?Happy Scale, Libra, MyFitnessPal, Lose It!, the Withings app and a free Weight Tracker compared: how each logs your weight, and who each suits.
• Best Workout Planner Apps Compared: Which Suits You?Fitbod, Hevy, Strong, JEFIT, Nike Training Club and a free Workout Planner compared: how each plans your training, and who each one suits.