Hobby

Calculate the ideal shooting distance to your subject from a flash unit's guide number, aperture and ISO.

Calculate the correct f-stop for flash photography from guide number, distance, and ISO. Instantly see the nearest standard f-stop and the correct distance for each aperture.

Estimate the lens focal length (mm) and 35mm equivalent you need from your subject distance, real size, and sensor width.

Enter a lens focal length and image sensor size to instantly calculate how wide a scene the camera captures: the horizontal, vertical, and diagonal angle of view. Includes presets for full frame, APS-C, Micro Four Thirds and more (plus custom sensor sizes) and shows the 35mm equivalent focal length too.

From focal length, f-stop, subject distance, and circle of confusion, calculate the front, rear, and total in-focus range plus the hyperfocal distance.

From focal length, shooting distance, and sensor size, calculate the real area captured in your photo (width x height) and the angle of view. Great for planning group and product shots.

From the number of people and each person's blink probability, calculate the chance everyone has their eyes open in a group photo, plus how many shots to take to avoid a blink.

Convert between a timecode (hours:minutes:seconds:frames) and total frames or total seconds using your frame rate. Built for video editing and supports 23.976 to 60 fps.

Calculate the image resolution (width × height in pixels and total megapixels) needed to print sharply at a given paper size and dpi, including L size, A4, and A3.

Convert a TV's diagonal inches and aspect ratio into the actual screen width, height, and diagonal in centimeters, plus the ideal viewing distance.

Enter an item's price, the points you hold, and the earn rate to instantly see your cash payment after redeeming points, the points you'll earn, and your effective discount.

Just enter the number of prize types to estimate the average pulls needed to complete a full gacha set. Add the cost per pull for an expected-cost estimate, or a target probability for the pulls required (assuming equal odds).

Estimate your car's annual, monthly, and per-kilometer running costs from automobile tax, insurance, shaken inspection, parking, fuel, and maintenance.

Enter hits and at-bats to get a baseball batting average in the standard .000 (three-decimal) format, plus the hits needed to reach marks like .300.

Enter hits, walks, hit-by-pitch, at-bats, and sacrifice flies to instantly compute a player's on-base percentage (OBP) to three decimal places. Unlike batting average, OBP credits the value of walks and hit-by-pitches.

Enter your singles, doubles, triples, home runs, and at-bats to instantly compute baseball slugging percentage (SLG) to three decimals, along with total bases and total hits.

Calculate OPS (On-base Plus Slugging), the all-in-one batting metric, by entering OBP and SLG directly or by entering hits, walks, hit by pitch, at bats, sacrifice flies, and total bases. OBP, SLG, and a rating are shown at once.

Instantly calculate earned run average (ERA) from earned runs and innings pitched. Enter innings as full innings plus outs or as a decimal, with the result shown to two decimal places.

Calculate a baseball winning percentage to three decimals from wins and losses. Ties are excluded, with games, wins, and losses also listed.

Calculate a pitcher's strikeout rate (K/9) from strikeouts and innings pitched. See how many strikeouts they average per 9 innings, shown to two decimals.

Enter putouts, assists, and errors to instantly compute a baseball fielding percentage to three decimals (e.g. .987). See total chances and the error breakdown in one table.

Just enter home runs allowed and innings pitched to instantly get a pitcher's HR/9. See how many home runs they give up per nine innings, shown to two decimal places.

Instantly find a pitcher's hit-by-pitch rate per 9 innings (HBP/9) from their hit batters and innings pitched.

Just enter your stolen bases and times caught stealing to instantly get the success rate. Shows the breakdown of attempts, successes, and failures, plus a comparison with the roughly 70% break-even mark.

Just enter caught stealing (CS) and stolen bases allowed (SB) to instantly calculate a catcher's caught stealing rate, shown both in baseball's three-decimal style (e.g. .350) and as a percentage. It also displays the total stolen base attempts so you can compare against the .350 strong-performance benchmark.

Just enter the wins and losses of the first-place team and the team you want to compare to instantly calculate the baseball "games behind" (GB). It also shows the win gap, loss gap, and win-percentage gap so standings are easy to read at a glance.

Just enter your team's number of games to instantly find the plate appearances needed to qualify for the batting title. Uses the NPB factor of 3.1, and entering your own plate appearances shows how many you still need, whether you qualify, and the required innings pitched for pitchers too.

Just enter wins, draws, and losses to compute soccer league points (Win×3 + Draw×1). Matches played and win rate appear too, and adding goals reveals goal difference.

Calculate a goalkeeper's save percentage (%) from saves and goals against. Also see shots faced and goals conceded per match.

Just enter the number of tries, conversions, penalty goals and drop goals to instantly work out a rugby team's total score. Add the match result and bonuses to get league table points too.

Calculate a dog or cat's obesity rate (%) from current and ideal weight, and see whether they are underweight, ideal, or obese along with a Body Condition Score (BCS) guide.

Estimate the daily water requirement of dogs and cats from their body weight. See the per-kg guide and how to factor in drinking water when feeding wet food.

Find out roughly how many generations ago a given year or number of years was. Choose the length of a generation (about 25 to 30 years) and see an estimate of the number of direct ancestors in that generation.

Just enter your dog's or cat's age to instantly see how old they are in human years. It accounts for how small, medium, and large dogs age differently, and shows the life stage plus a handy age-conversion chart.

Estimate the daily calories (DER) a dog or cat needs from its body weight and life stage (intact or neutered, puppy or kitten, senior, weight loss and more). See the resting energy requirement (RER) and activity factor breakdown too.

Estimate how long your air will last from tank volume, pressure, depth and respiratory minute volume (RMV).

Turn your 10 cm swatch gauge (stitches and rows) into the stitch and row counts needed for any finished width and height. Perfect for resizing knitting patterns.

Estimate, from your contact point height, the geometry a flat serve needs to clear the net and land inside the service box. See the minimum contact height to land it straight and a guide to the allowable downward angle.

Enter the outer dimensions (width, depth, height) and board thickness of a wooden box to calculate the board sizes and counts for all 6 faces (bottom, lid, front/back, sides), plus the total board area and the inner size and volume.

Estimate the amount of potting soil (in liters) you need from a round pot's rim diameter, base diameter and depth. Supports watering-space deduction and totals for multiple pots.

Enter the inside width, depth and height of a rectangular planter plus the water space, and instantly get the liters of potting soil needed, the total for several planters, and how many store-bought soil bags to buy.

Decode the last 4 digits of the DOT code (week + year) on your tire sidewall to find the production date (year, week, approximate month), the tire's age, and the 10-year replacement guideline.

Convert between binary, octal, decimal and hexadecimal, plus any base from 2 to 36. See your value listed in every common base at once.

Compute AND, OR, XOR, NOT, and left/right shifts on two integers and view the result in binary, octal, decimal, and hexadecimal, with the full bit pattern.

Enter an IPv4 address and a prefix length (CIDR) to instantly get the network and broadcast addresses, usable host range and host count, subnet mask, and wildcard mask. The binary representation of each value is listed too.

Calculate bug density (bugs per KLOC), test density, and bugs found per test case from your source size, test case count, and detected bugs. A quick way to build software quality metrics.

Convert any date, time, and time zone (JST/UTC) into a Unix timestamp (epoch seconds) starting from January 1, 1970. Milliseconds, ISO 8601, and the UTC equivalent are shown at the same time.

Convert a UNIX timestamp (seconds or milliseconds) into a readable date and time in JST or UTC, with the weekday and ISO 8601 string included.

Convert between MIPS (million instructions per second) and average instruction execution time in nanoseconds. Also derive MIPS from clock frequency and CPI. Great for CPU performance study.

Apply Moore's law (density doubling roughly every 2 years) to project a future value, plus the number of doublings, growth multiple, and annual growth rate.

Estimate how long a download or upload takes from a file size and connection speed. Factors in transfer efficiency to show a realistic effective-speed estimate.

Calculate the effective transfer speed (Mbps and MB/s) from the data size and the time a download or upload took. Conversions to bps and Bps are shown at the same time.

Instantly calculate your bounce rate (%) from bounced and total sessions. Shows non-bounced sessions too.

Instantly calculate a page's exit rate (%) from its exits and page views (PV). Shows continued visits and continuation rate too, perfect for site analytics.

Instantly work out your CVR from conversions and sessions. Includes a table that back-calculates the conversions needed to reach a target CVR.

Instantly calculate click-through rate (CTR) from your clicks and impressions. Perfect for checking the response rate of ads, emails, and search results.

Just enter your conversions and clicks to instantly get the click-to-conversion rate (CTC). See at a glance how well your ads and landing pages are performing.

Calculate cost per click (CPC) from your ad spend and clicks, and estimate how many clicks a given budget can buy.

Enter your ad spend and number of conversions to instantly calculate your cost per acquisition (CPA). Add a target CPA to see how many conversions the same budget could buy and whether you are hitting your goal.

Just enter your investment and profit (or revenue and cost) to instantly get ROI and the return multiple. See the payback of ad spend or inventory at a glance.

Instantly calculate ROAS (return on ad spend) from your ad-driven revenue and ad spend. See how much revenue each dollar of ad spend earns.

Just enter a starting value, an ending value, and the number of years to instantly calculate the compound annual growth rate (CAGR). You also get the total growth over the whole period, making it easy to compare how revenue or investments grew on an annualized, apples-to-apples basis.

Project future sales from your current revenue and an annual growth rate using compound growth, with a year-by-year breakdown.

Calculate the percentage (%) from a part and a whole, work backward to find a part from a percentage, or break down multiple items into a composition ratio shown in a table.

Just enter the concentrate concentration, the target concentration (% or ppm), and how much you want to make to instantly get the amount of concentrate needed and the water to add. You can also specify by dilution ratio, making it easy to mix cleaners, disinfectants, and sodium hypochlorite solutions.

Enter the site area and total floor area to instantly get the floor area ratio (%). You can also work backward from a permitted ratio to find how much floor area you can build, plus an explanation of road-width limits.

Calculate the building coverage ratio (%) from site area and building footprint. Reverse-calculate the maximum buildable area from a zoning limit, with corner-lot relaxation explained.

Just paste your numbers to instantly compute summary statistics including the mean, variance, standard deviation, and median.

Paste a set of test or class scores and instantly get each entry's T-score, the mean, standard deviation, and rank. Enter any score to see exactly what T-score and rank it corresponds to.

Just enter your numbers and instantly get all three means at once: arithmetic, geometric, and harmonic.

Paste a list of numbers and instantly get the sum, mean, maximum, minimum, range (max − min), and count. Accepts line breaks or commas, perfect for quickly summarizing test scores, sales figures, or measurements.

Just enter your class midpoints and frequencies to instantly get the mean (weighted average), variance, and standard deviation of a frequency distribution table. See both population and sample values, plus a full x×f breakdown.

Run an independent two-sample t-test (Welch or Student) by entering each group's raw data, or just the mean, standard deviation and sample size. Get the t-statistic, degrees of freedom and approximate p-value, with a quick significant/not-significant verdict at the 5% level.

Sort a list of numbers in ascending or descending order, with ranks and original positions shown in a table. The maximum and minimum are highlighted at a glance.

Paste numbers into Column A and Column B and run row-by-row addition, subtraction, multiplication, or division all at once. See the result column plus the total and average of each column, computed automatically.

Enter each party's votes and the total number of seats to instantly allocate seats with the D'Hondt method (dividing votes by 1, 2, 3… and awarding seats to the largest quotients). A quotient table shows the full allocation process at a glance.

Add or subtract two 2D or 3D vectors and instantly get the result vector along with its magnitude (norm), dot product, and the angle between the vectors.

Enter each item's base- and current-period prices and quantities to instantly compute the Laspeyres, Paasche, and Fisher price indices. See how the overall price level has shifted against a base of 100, with a per-item breakdown.

Estimate the lost profit from traffic accidents and similar cases using base income, living expense deduction rate, loss of earning capacity rate, working years, and the Leibniz coefficient.

Compute the process capability indices Cp and Cpk from spec limits and a mean & standard deviation (or raw measurement data), with a rating to interpret the result.

Apply square, square root, logarithm, trigonometric and other functions to a list of numbers at once, and compare each input with its result in a table. Multiplying or adding a constant is supported too.

Apply a two-variable operation such as sum, difference, product, quotient, power, Euclidean distance, or average to two columns of numbers (x and y) at once, and view each row's result plus the total and average in a table.

Just paste your "label,value" data to instantly build a Pareto chart: bars sorted from largest to smallest with a cumulative-share line on top. It also shows a share/cumulative table and an 80% line so the few items that matter most stand out at a glance.

Enter the five-number summary—minimum, first quartile, median, third quartile, and maximum—to instantly draw a horizontal box plot and review summary values such as the interquartile range (IQR) in a table.

Paste your raw numbers to compute the quartiles, IQR, and outliers, then draw a box plot automatically. The five-number summary is shown in a table too.

A free tool that calculates the composition ratio just from item names and values, instantly drawing a color-coded pie chart and a table of shares.

Just paste your numbers and a line chart is drawn automatically. Compare multiple series and see the min, max, and average summarized at the same time. Great for visualizing trends in sales, traffic, temperatures, and more.

Just enter labels and values to instantly draw a vertical bar chart. Get a clean chart with axes, gridlines, and value labels, plus the total, average, maximum, and each item's percentage share. Great for quickly visualizing survey results, test scores, or sales comparisons.

Paste your (x, y) data and instantly build a scatter plot, complete with the correlation coefficient and a least-squares regression line.

Paste your numbers and instantly build a frequency distribution and histogram. Choose the bin count and review the mean, standard deviation, and a full frequency table.

Just enter your numbers to plot each one as a point on a ticked number line. Equal values stack up, and the minimum, maximum, and mean are shown at a glance. Custom display range and tick spacing supported.

Paste three columns of x, y and z, then apply operations like sum, product, average or x×y+z all at once. See per-row results, totals, averages and a bar chart together.

Apply two operations at once—sum, difference, product, quotient and more—to two columns of numeric data (x and y), and review the per-row results in a table and chart.

Apply three operations such as sum, product, and mean to your x, y, and z columns at once. Results appear in a table and an SVG bar chart, with the sum and mean of each result column tallied automatically.

Just enter a percentage point x (z-score) and get the standard normal density f(x) plus the lower, upper, and inner cumulative probabilities automatically. A bell-curve graph shades each probability as an area so you can see it at a glance.