ForHosting KIT
Free tools that work
right in your browser.
Calculators, converters, PDF, text, images and much more — each with its own page. Type your data and get the result right here, with no sign-up and without your data leaving your device. Need them in your own app? The same tools are available by API.
REST APILive
EmailLive
Webkit.forhosting.comLive
TelegramLive
iOS & AndroidBuilding
WhatsAppComing
7830tools
7432free in your browser
8languages
6channels
Find your tool
Search in your own words or filter by category.
🔬 ScienceFree
Photon Flux from Power Calculator
Divide the beam power by the energy of one photon to get photons per second: one milliwatt can mean about 2.5 × 10¹⁵ photons every second, because each photon…
B
Runs in your browser
🔬 ScienceFree
Unpolarized light through polarizer calculator
Unpolarized light of intensity 120 leaves an ideal polarizer at 60, exactly half, whatever the polarizer's angle.
B
Runs in your browser
🔬 ScienceFree
Wavelength from photon energy
Turn photon energy into wavelength straight away: 2.25 eV gives 551.040881925 nm, green light. Enter electronvolts, millielectronvolts, kiloelectronvolts…
S
Runs in your browser
🔬 ScienceFree
Exposure value from aperture and shutter calculator
Turn an aperture and a shutter time into one exposure value at ISO 100: f/8 at 1/125 s, entered as 0.008, gives EV 12.966, so you can compare two camera…
B
Runs in your browser
🔬 ScienceFree
Illuminance from luminous intensity
Know how bright a surface will be before you place the lamp: 100 candela at 2 metres puts 25 lux on a surface facing the source, by dividing intensity by…
P
Runs in your browser
🔬 ScienceFree
ISO stops difference calculator
See exactly how far apart two ISO settings are: going from ISO 100 to ISO 800 is a ratio of 8, or 3 stops more sensitive, and in-between values keep their exact…
F
Runs in your browser
🔬 ScienceFree
Luminous efficacy calculator
Compare lamps by how much light each watt buys: a source giving 800 lumens while drawing 10 watts reaches 80 lumens per watt, and your original figures stay…
K
Runs in your browser
🔬 ScienceFree
Shutter speed from exposure value
At EV 12, f/5.6 and ISO 100, the matching shutter time is 0.00765625 s, shown as 1/131 s. Keep the aperture you want for depth of field and read the time to…
S
Runs in your browser
🔬 ScienceFree
Temperature from radiated power
A surface of 1 m² with emissivity 1 that radiates 459.300327939 W is at 300 K. Enter the radiated power, the area and the emissivity to recover the temperature…
A
Runs in your browser
🔬 ScienceFree
Wien displacement law calculator
A blackbody at 5778 K, like a star’s photosphere, shines brightest in visible light. Enter any absolute temperature and Wien's law returns the peak wavelength…
F
Runs in your browser
🔬 ScienceFree
Fiber material dispersion calculator
Estimate how much a light pulse spreads in glass fiber: a dispersion of 17 ps/(nm·km), a 2 nm wide source and 10 km of fiber widen each pulse by 340 ps.
S
Runs in your browser
🔬 ScienceFree
Fiber relative refractive index difference
Enter the core and cladding indices and get the normalized contrast Δ: a core of 1.48 over a cladding of 1.46 gives Δ = 0.01342220599, shown next to the…
P
Runs in your browser
🔬 ScienceFree
Fiber total loss calculator
Get the distance-dependent loss of a fiber span in one step: 0.35 dB/km over 12.5 km is 4.375 dB, the term that goes straight into your link budget before…
K
Runs in your browser
🔬 ScienceFree
Flash distance from guide number
Know where to stand before you shoot: a metric guide number of 36 at f/8 lights a subject correctly at 4.5 metres, in the same unit as the guide number on your…
A
Runs in your browser
🔬 ScienceFree
Optical path length calculator
Light crossing 0.25 m of material with a refractive index of 1.5 covers an optical path of 0.375 m: distance times index, shown step by step.
F
Runs in your browser
🔬 ScienceFree
Single-mode fiber cutoff wavelength calculator
A fiber with a 4.1 µm core radius and an NA of 0.14 turns single-mode above 1499.60431032 nm. Enter the radius and numerical aperture to check a design or a…
B
Runs in your browser
🔬 ScienceFree
Optical etendue calculator
Multiply source area by solid angle to get etendue: 0.0001 m² of emitter spreading into 0.02 sr gives 0.000002 m²·sr, a value that no lossless lens or mirror…
B
Runs in your browser
➗ MathFree
IQR outlier detection calculator
Spot the values that sit far outside the middle half of your data: in 1, 2, 2, 3, 4 and 100 the fences fall at −1 and 7, so 100 is the only outlier.
B
Runs in your browser
➗ MathFree
Median absolute deviation calculator
For 1, 1, 2, 2, 4, 6 and 9 the median is 2 and the median absolute deviation is 1: the distances from 2 are 1, 1, 0, 0, 2, 4 and 7, and their median is 1.
K
Runs in your browser
➗ MathFree
Mode of a dataset calculator
In 1, 2, 2, 3 and 4 the mode is 2, reached twice, and a frequency table shows how often each value appears.
P
Runs in your browser
➗ MathFree
Population variance calculator
The eight values 2, 4, 4, 4, 5, 5, 7 and 9 have a mean of 5 and a population variance of 4. Paste every value of the group and get the count, mean, sum of…
K
Runs in your browser
➗ MathFree
Quintile calculator
For the numbers 1 to 10, the four quintile cuts are 2.8, 4.6, 6.4 and 8.2, the 20th, 40th, 60th and 80th percentiles.
S
Runs in your browser
➗ MathFree
Standard error of the mean calculator
For 2, 4, 4, 4, 5, 5, 7, 9 the mean is 5 and its standard error is about three quarters of a unit, the sample standard deviation over the square root of 8.
A
Runs in your browser
➗ MathFree
Winsorized Mean Calculator
Average data without letting extremes take over: for 1, 2, 3, 4 and 100 with a fraction of 0.2 per tail, the 1 becomes 2, the 100 becomes 4 and the winsorized…
F
Runs in your browser
➗ MathFree
Class Width Calculator for Frequency Tables
Data running from 12 to 92 have a range of 80, so 8 classes give a class width of exactly 10. Enter the smallest value, the largest value and the number of…
B
Runs in your browser
➗ MathFree
Cumulative Frequency Calculator for Class Counts
Class counts of 4, 7, 3 and 6 become running totals of 4, 11, 14 and 20, and the last figure is your total number of observations.
F
Runs in your browser
➗ MathFree
Grouped data mode calculator
Estimate the most common value when data come grouped in classes: with boundaries 0, 10, 20, 30 and 40 and counts 5, 9, 12 and 7, the mode is 23.75, inside the…
K
Runs in your browser
➗ MathFree
Moment coefficient of skewness calculator
For 1, 2, 3, 4, 5 and 12 the mean is 4.5, the third central moment is 60 and the moment coefficient of skewness is above 1, so the sample is labelled…
P
Runs in your browser
➗ MathFree
Standardized moment calculator
For 1, 2, 3, 4, 5, 12 at order 3, the mean is 4.5 and the third central moment is 60; dividing it by the standard deviation cubed gives a positive skewness with…
S
Runs in your browser
➗ MathFree
Kendall tau correlation calculator
Check whether two series rise and fall in the same order: for 1, 2, 3, 4 against 1, 3, 2, 4 there are 5 agreeing pairs and 1 disagreeing pair out of 6, so tau…
F
Runs in your browser
➗ MathFree
Mean deviation about median calculator
For 1, 2, 3, 4 and 100 the median is 3 and the mean deviation about it is 20.2: the distances from the median add up to 101, and 101 divided by 5 is 20.2.
S
Runs in your browser
➗ MathFree
Pearson mode skewness calculator
With a mean of 12, a mode of 10 and a standard deviation of 4, Pearson's mode skewness is 0.5, a right-skewed shape.
A
Runs in your browser
➗ MathFree
Regression intercept calculator
For x of 1 to 5 with y values 2, 4, 5, 4 and 5, the least-squares line crosses the y axis at 2.2. Enter paired x and y lists of the same length to get the…
K
Runs in your browser
➗ MathFree
Sample covariance calculator
For x values 2, 4, 6, 8 and y values 1, 3, 5, 7, the cross-deviations add up to 20 and are divided by 3, a positive covariance: the two series rise together.
B
Runs in your browser
➗ MathFree
Scott's rule bin width calculator
For the eight values 2, 4, 4, 4, 5, 5, 7, 9, Scott's rule gives a bin width that covers their range of 7 in 2 bins.
P
Runs in your browser
➗ MathFree
Concordance correlation coefficient calculator
Two identical series from 1 to 5 give a concordance coefficient of 1, but shift or rescale one of them and it drops below 1 while Pearson's r stays at 1.
S
Runs in your browser
➗ MathFree
Cubic regression calculator
Enter five points that lie on a cubic and you get its coefficients back exactly: 1, 2, −1 and 1 for the constant, linear, quadratic and cubic terms.
F
Runs in your browser
➗ MathFree
Line of best fit calculator
Draw a straight trend line through paired data: for x of 1 to 5 and y of 2, 4, 5, 4 and 5, the least-squares line has slope 0.6 and intercept 2.2, with a…
K
Runs in your browser
➗ MathFree
Mean Absolute Percentage Error (MAPE) Calculator
Four forecasts that miss their actual values by 10%, 5%, 10% and 10% give a MAPE of 8.75%: the average size of the miss as a percentage, with misses above and…
F
Runs in your browser
➗ MathFree
Partial correlation calculator
If x and y correlate at 0.8, x and z at 0.5 and y and z at 0.4, the partial correlation of x and y controlling for z is about 0.76: most of their link survives…
P
Runs in your browser
➗ MathFree
Power regression calculator
The points (1, 3), (2, 12), (4, 48) and (8, 192) follow the power curve 3·x² exactly: a is 3, b is 2 and the log-space R² is 1.
S
Runs in your browser
➗ MathFree
Standard error of the estimate
For x from 1 to 5 and y of 2, 4, 5, 4, 5, the best-fit line has slope 0.6 and intercept 2.2, the squared residuals add up to 2.4, and the standard error of the…
A
Runs in your browser
➗ MathFree
At least one event probability calculator
With a 0.2 chance on each trial and 5 trials, the chance of at least one success is 0.67232. You also see the chance of no success at all, so you can check that…
B
Runs in your browser
➗ MathFree
Coin toss streak probability calculator
In 10 fair tosses, the chance of seeing at least one run of 3 heads in a row is 0.5078125, just over half.
F
Runs in your browser
➗ MathFree
Complement probability calculator
An event with a probability of 0.35 has a complement of 0.65, the chance it does not happen. Enter any probability from 0 to 1 to get both sides as decimals and…
A
Runs in your browser
➗ MathFree
Expected payoff calculator for games and gambles
A 10 % chance to win 100 adds 10 to the average, while a 50 % chance to lose 10 takes away 5. Enter every result with its probability and see the long-run…
B
Runs in your browser
➗ MathFree
Lottery jackpot odds calculator
See how unlikely the top prize really is: a 6-from-49 game has 13,983,816 possible tickets, so matching every number is 1 in 13,983,816, or about 13,983,815 to…
S
Runs in your browser
➗ MathFree
Marginal probability calculator
For the joint table 0.1, 0.2, 0.3, 0.4, the row marginal is 0.3 and 0.7 and the column marginal is 0.4 and 0.6.
A
Runs in your browser
➗ MathFree
Mutually Exclusive Events Checker
With P(A) of 0.35, P(B) of 0.4 and a joint probability P(A and B) of 0, the two events are mutually exclusive: they cannot happen in the same outcome.
K
Runs in your browser
➗ MathFree
Binomial Mean and Variance Calculator
With 20 trials and a 0.35 chance of success on each, a binomial count averages 7 successes with a variance of 4.55.
B
Runs in your browser
➗ MathFree
Expected value of a dice roll
Two six-sided dice average a total of 7, with possible sums running from 2 to 12. Enter how many dice and how many sides, and get the expected total, the mean…
S
Runs in your browser
➗ MathFree
Geometric CDF calculator
See how likely the first success is to arrive in time: with a 0.25 chance per attempt, at least one success within 4 attempts has probability 0.68359375, and…
F
Runs in your browser
➗ MathFree
Poisson at least probability calculator
With an average of 2.5 events per interval, the chance of at least 3 is 0.4561868841166705. Enter the average rate and the minimum count you care about to get…
P
Runs in your browser
➗ MathFree
Poisson PMF calculator
Exactly 3 events when 2.5 are expected on average has a probability of 0.21376301724973648. Type the rate and the count you care about to isolate that single…
A
Runs in your browser
➗ MathFree
Probability of Neither Event Calculator
There is a 0.4 chance that neither A nor B happens when P(A) is 0.4, P(B) is 0.3 and their overlap is 0.1.
K
Runs in your browser
➗ MathFree
Two-stage probability tree calculator
If rain has a probability of 0.3 and being late given rain 0.4, the rain-then-late path has a probability of 0.12.
F
Runs in your browser
➗ MathFree
Discrete RV standard deviation
A fair die, with the values 1 to 6 at probability 1/6 each, has a mean of 3.5. Enter your own table of values and probabilities, which must add up to one, and…
P
Runs in your browser
➗ MathFree
Continuous uniform CDF calculator
For a uniform distribution from 2 to 10, the chance of a value at or below 5 is 0.375. Enter the two bounds and a point: values below the range give zero…
K
Runs in your browser
➗ MathFree
Negative Binomial Mean and Variance Calculator
With a target of 5 successes and a 0.4 chance of success on each trial, you can expect 7.5 failures on average before the fifth success.
B
Runs in your browser
➗ MathFree
Normal distribution CDF calculator
If x equals the mean, such as 0 on the standard normal curve, the cumulative probability is 0.5: half the curve lies to its left.
S
Runs in your browser
No capabilities match your search.
How it works
1
Get your key
Create an account with your email and add balance when you need it. No subscription, no sales call.
2
Call the endpoint
One authenticated POST. The API returns a task_id immediately — copy-paste snippets in five languages on every page.
3
Collect the result
Receive a signed webhook the moment it's ready, or fetch a signed link. A failed task is never charged.
Pay only for what you use
No subscription. Free tools run in your browser; paid tasks draw from your balance, which never expires.
Free tools
$0.00
On-device utilities — hash, QR, JSON, Text→PDF and more — run in your browser. No account, no limits.
Pay-as-you-go
Per task
$0.002+
The full API — 7800+ capabilities — billed only for what you run, from $0.002 per call. No monthly fee.
Balance
$10.00+
Top up your balance and spend it across web, API and the app. It never expires.