All Calculators

Our free online scientific calculator handles everything from basic arithmetic to advanced mathematics. Compute sine, cosine, and tangent in both degree and radian modes, evaluate natural and base-10 logarithms, raise numbers to any power, and extract square roots in seconds. Additional functions include factorials, absolute value, reciprocals, the constants π and e, and a percentage key. Every calculation is saved to a scrollable history so you can review or reuse previous results without retyping. Full keyboard support means you can type expressions naturally and press Enter to evaluate — no mouse required. Whether you are solving a trigonometry assignment, checking a physics formula, or verifying an engineering calculation, CalcKit's scientific calculator gives you accurate results instantly, right in your browser.

Convert between more than 50 units across seven categories — length, weight, temperature, area, volume, speed, and time — with live results that update as you type. Switch the direction of any conversion with a single tap using the swap button. The length category includes Indian land units such as Bigha, Guntha, Kattha, and Gaj alongside the standard metric and imperial units, making it especially useful for property and land-area calculations. Temperature conversions handle Celsius, Fahrenheit, and Kelvin correctly using the proper offset formulas rather than simple multipliers. Whether you need to convert kilometres to miles for a road trip, kilograms to pounds for a recipe, or square metres to acres for a land deal, CalcKit's unit converter delivers precise answers without ads or distractions.

CalcKit's percentage calculator covers the three most common percentage problems in one clean interface. Use Basic % mode to find what a given percentage of any number is — for example, what is 18% of 4,500? Switch to Increase / Decrease mode to calculate the percentage change between two values, useful for tracking price changes, exam score improvements, or sales growth. The % Difference mode computes the relative difference between two numbers symmetrically, which is the standard formula used in scientific comparisons. Each result is accompanied by the plain-English formula so you can understand exactly how the answer was reached — ideal for students learning percentage concepts for the first time. Press Enter in any input field to calculate instantly without reaching for the mouse.

Enter any date of birth and instantly see your precise age broken down into years, months, and days. The calculator also shows your age expressed as total months elapsed, total weeks lived, and total days — useful for filling out forms that ask for age in a specific unit, or simply for satisfying curiosity. An optional 'age as of' date field lets you calculate age at any past or future reference date, making it handy for legal documents, insurance forms, school admission cut-off checks, and retirement planning. All calculations account for leap years and varying month lengths, so the result is always accurate to the day.

Body Mass Index (BMI) is a widely used screening tool that relates your weight to your height to give a quick indication of whether you fall within a healthy weight range. CalcKit's BMI calculator supports both metric inputs (kilograms and centimetres) and imperial inputs (pounds and feet/inches), so you can use whichever unit system you are comfortable with. After calculating, the result is displayed alongside its WHO category — Underweight, Normal weight, Overweight, or Obese — and the plain formula is shown so you understand exactly how BMI is derived. Note that BMI is a population-level screening measure and does not account for muscle mass, bone density, or body composition; always consult a healthcare professional for personalised health advice.

Calculate your Grade Point Average quickly by adding as many courses as you need, assigning credit hours to each, and selecting a letter grade from A+ down to F. The calculator uses the standard 4.0 scale with full plus/minus support — A+ and A both map to 4.0, A− to 3.7, B+ to 3.3, and so on — and weights each course by its credit hours so higher-credit subjects have proportionally more influence on your final GPA. Add or remove courses freely, and the cumulative GPA updates instantly. This tool is useful for students tracking their academic standing, checking eligibility for scholarships or honours programmes, or planning which courses to retake to improve their overall average.

India's Goods and Services Tax (GST) applies at four main rates — 5%, 12%, 18%, and 28% — plus a custom rate option for special categories. CalcKit's GST calculator works in two directions: Add GST mode takes a pre-tax (exclusive) amount and computes the GST and final payable total, while Remove GST mode works backwards from a GST-inclusive price to extract the base amount and the tax component. Every result includes a full breakdown showing CGST and SGST (each at half the applicable rate, for intra-state transactions) as well as the equivalent IGST amount (the full rate, for inter-state transactions). Whether you are a freelancer raising an invoice, a business owner verifying a vendor bill, or a student studying indirect taxation, this calculator gives you the exact figures in seconds.

Plan your long-term savings with CalcKit's EPF and PPF growth predictor. The EPF (Employees' Provident Fund) tab calculates your projected corpus based on your Basic Salary plus DA, current and retirement age, existing balance, and the prevailing interest rate (default 8.25%). It models both the employee contribution (12% of Basic+DA) and the employer contribution (3.67% towards EPF) with monthly compounding, giving you a realistic picture of what your provident fund will be worth at retirement. The PPF (Public Provident Fund) tab lets you enter your annual deposit (up to the ₹1.5 lakh limit), tenure (minimum 15 years), existing balance, and interest rate (default 7.1%), and applies annual compounding as per PPF rules. Both tabs display results in readable Lakhs or Crores, show a principal-versus-interest bar chart, and offer an expandable year-by-year table so you can see exactly how your corpus grows over time.

Calculate your Indian income tax liability for FY 2025-26 (AY 2026-27) under both the new and old tax regimes and instantly see which one saves you more money. The new regime uses the revised Budget 2025 slabs — 0% up to ₹4 lakh, 5% from ₹4–8 lakh, 10% from ₹8–12 lakh, 15% from ₹12–16 lakh, 20% from ₹16–20 lakh, 25% from ₹20–24 lakh, and 30% above ₹24 lakh — with a ₹75,000 standard deduction and a full Section 87A rebate for taxable incomes up to ₹12 lakh. The old regime applies the familiar 0/5/20/30% slabs with a ₹50,000 standard deduction and allows deductions under Section 80C (up to ₹1.5 lakh), Section 80D (up to ₹25,000), NPS 80CCD(1B) (up to ₹50,000), HRA, and other exemptions. The calculator also applies the correct surcharge tier for high incomes and adds the 4% Health and Education Cess, then shows a full slab-wise breakdown and your effective tax rate. A side-by-side regime comparison highlights exactly how much you save by choosing the better option.

Make smarter investment decisions with CalcKit's four-in-one mutual fund calculator. The SIP tab uses the standard future-value formula to show how a fixed monthly investment grows over time at a given expected annual return, displaying total amount invested, estimated gains, and final corpus alongside a principal-versus-returns bar. The Lump Sum tab does the same for a one-time investment using compound interest. The CAGR tab works in reverse — enter an initial value, a final value, and the number of years to find the Compounded Annual Growth Rate, which is the standard benchmark for comparing mutual fund performance. The Inflation-Adjusted tab goes a step further by factoring in an inflation rate to show the real purchasing power of your future corpus, so you can see what your money will actually be worth in today's terms. SIP and Lump Sum results include an expandable year-by-year breakdown table for detailed planning.