Toolstud.io calculators and converters
Toolstud.io is a collection of free online calculators and converters for professionals and enthusiasts in photography, video production, music, web development, and data analysis. All tools run directly in the browser — no login, no installation, no tracking.
What you can do
- Photo & image — calculate megapixels, estimate file sizes for RAW/TIFF/JPEG, convert DPI to print dimensions, and analyze aspect ratios
- Video & screen — convert framerates, compute bitrates for streaming and cinema, calculate screen sizes, and compare projector luminance in foot-lamberts
- Music — find BPM, calculate song length from bars and tempo, generate musical scales with exact frequencies, and convert between Hz and musical notes
- Data & bandwidth — convert file sizes, estimate download times, compare bandwidth units, and calculate power consumption
- Color — convert between RGB, CMYK, HSL, and hex color codes, find web-safe alternatives, and explore HTML color names
- Calculators — speed conversion, acceleration, distance, and exponential growth calculations
- Finance — fuel cost, EV charging cost, mortgage, and CO2 emission calculators
- Network & web — SSL certificate checks, SPF record validation, URL encoding, and CSP header analysis
Who is this for?
Photographers estimating storage needs for a shoot. Video editors preparing files for delivery. Musicians working out song structure. Web developers debugging headers. Students learning unit conversions. If you need a quick, reliable answer without signing up for anything, these tools are for you.
About the author
Toolstud.io is built and maintained by Peter Forret, a Brussels-based developer and technologist. The first tools were created in the early 2000s and the collection has grown steadily since. Use them freely (within reason), and if you have suggestions, get in touch.
Color calculators & converters
CMYK conversion
Convert CMYK color → RGB, HSV, XYZ
Convert CMYK color → RGB, HSV, XYZ
HTML Color list
List of named HTML colors
List of named HTML colors
RGB conversion
Convert RGB color → CMYK, HSV, XYZ
Convert RGB color → CMYK, HSV, XYZ
Websafe Color list
List of websafe colors
List of websafe colors
Data calculators & converters
Bandwidth convert
Convert Mbps ⇆ KB/s, GB/day, TB/week
Convert Mbps ⇆ KB/s, GB/day, TB/week
Download calculator
Calculate download time from bandwidth & file size
Calculate download time from bandwidth & file size
Data size calculator
Calculate file size from bandwidth & time
Calculate file size from bandwidth & time
Finance calculators & converters
EV mileage calculator
How much $ does your EV car use in kWh per year?
How much $ does your EV car use in kWh per year?
Fuel Cost calculator
How much $ does your car fuel cost per year?
How much $ does your car fuel cost per year?
Natural Gas calculator
How much $ does your heating gas cost?
How much $ does your heating gas cost?
Mortgage loan calculator
Calculate monthly payments for a mortgage loan
Calculate monthly payments for a mortgage loan
Health calculators & converters
BMI calculator
Calculate your Body Mass Index
Calculate your Body Mass Index
Corpulence calculator
Calculate your Corpulence Index
Calculate your Corpulence Index
Music calculators & converters
Beats-per-minute
Convert BPM to Hz, bar length, fractions
Convert BPM to Hz, bar length, fractions
Audio delay
Calculate audio delay length in msec
Calculate audio delay length in msec
Music Frequency
Convert pitch to musical note and wavelength
Convert pitch to musical note and wavelength
Song length
Calculate song length from BPM
Calculate song length from BPM
Music Scale
Generate scales with frequencies
Generate scales with frequencies
Tap your tempo
Tap to find the BPM of a song or a heartbeat
Tap to find the BPM of a song or a heartbeat
Photo calculators & converters
Aspect ratio
Image Width x Height → aspect ratio
Image Width x Height → aspect ratio
Aspect Fit
Fit an image on a screen
Fit an image on a screen
Composition Calculator
Focal length, distance, crop factor → image composition
Focal length, distance, crop factor → image composition
Depth-of-Field Calculator
Aperture, focal length, distance, crop → depth-of-field
Aperture, focal length, distance, crop → depth-of-field
DPI calculator
Print Width x Height and dpi → megapixels
Print Width x Height and dpi → megapixels
Image filesize calculator
Image Width x Height JPG/RAW/PNG → bytes
Image Width x Height JPG/RAW/PNG → bytes
Light calculator (EV)
Aperture, shutter time, ISO → Exposure Value
Aperture, shutter time, ISO → Exposure Value
Megapixel calculator
Image Width x Height → megapixels
Image Width x Height → megapixels
Megapixel Aspects
See megapixels in different aspect ratios
See megapixels in different aspect ratios
Portrait distance
portrait distance, composition, crop factor, focal length
portrait distance, composition, crop factor, focal length
Physics calculators & converters
Acceleration calculator
Convert m/s² into in/s², g
Convert m/s² into in/s², g
Battery Capacity (Wh)
What does the kWh of a battery mean?
What does the kWh of a battery mean?
Distance calculator
Speed x time → distance
Speed x time → distance
Exponential growth
Exponential growth / logarithmic decay
Exponential growth / logarithmic decay
Gladwell's 10000 hours
Deliberate practice according to Malcolm Gladwell
Deliberate practice according to Malcolm Gladwell
Speed converter
m/s ⇆ km/h, mph, mach
m/s ⇆ km/h, mph, mach
tCO2e Calculator
Calculate your carbon footprint in ton C02/year
Calculate your carbon footprint in ton C02/year
Frequency Calculator
Hertz -> wavelength, spectrum
Hertz -> wavelength, spectrum
Electrical power
Volt x Amp → Watt, kWh, Ah, Joule, calorie
Volt x Amp → Watt, kWh, Ah, Joule, calorie
Wavelength Calculator
Wavelength -> Hz, spectrum
Wavelength -> Hz, spectrum
Video calculators & converters
Audio file size calculator
Estimate audio file size for (un)compressed audio
Estimate audio file size for (un)compressed audio
Common bitrates
List of common video bitrates (Prores, DV, DCP, MPEG)
List of common video bitrates (Prores, DV, DCP, MPEG)
DCP file size
Calculate DCP audio and video filesizes
Calculate DCP audio and video filesizes
Foot-Lambert Calculator
Foot-Lambert Calculator for luminance of a screen
Foot-Lambert Calculator for luminance of a screen
Screen size
Calculate screen size from diagional and aspect ratio
Calculate screen size from diagional and aspect ratio
Video bitrate
Estimate video bitrate based on resolution, fps and bit depth
Estimate video bitrate based on resolution, fps and bit depth
Frame rate convert
Framerate conversion with ffmpeg and sox
Framerate conversion with ffmpeg and sox
Video file size calculator
Estimate video file size from resolution and duration
Estimate video file size from resolution and duration
Web calculators & converters
Content Security Policy
Create your Content Security Policy header fast!
Create your Content Security Policy header fast!
Redirection check
Is your site redirection correctly configured?
Is your site redirection correctly configured?
Security Policy Framework check
Is your SPF correctly configured?
Is your SPF correctly configured?
HTTPS config check
Is your site correctly configured for HTTPS?
Is your site correctly configured for HTTPS?
HTML char map
View all special HTML characters «»
View all special HTML characters «»
Emoji char map
View all special Unicode characters 🥠
View all special Unicode characters 🥠
HTML encoder
(HTML/URL) Encode text full of àçčéñtš
(HTML/URL) Encode text full of àçčéñtš
SEO Performance
Check your site on 10+ performance test sites
Check your site on 10+ performance test sites
URL encoder
URL Encode text full of àçčéñtš
URL Encode text full of àçčéñtš
How could you use these tools?
Recent Blog Posts
How does a flat image fit on a scope screen?
I had to calculate the dimensions of a flat DCP (1920x1080) on a scope (aspect ratio 2.39) cinema screen, and this is a perfect task for the aspect fit calculator. Let’s...
I had to calculate the dimensions of a flat DCP (1920x1080) on a scope (aspect ratio 2.39) cinema screen, and this is a perfect task for the aspect fit calculator. Let’s...
How does an image (aspect) fit on a screen?
When you have an image with a certain aspect ratio (width/height), and you want to show it on a screen with a different aspect ratio, you have 2 simple options: extend with...
When you have an image with a certain aspect ratio (width/height), and you want to show it on a screen with a different aspect ratio, you have 2 simple options: extend with...
The new beats-per-minute calculator
The BPM (beats-per-minute) calculator was up for an update. The calculator is used to calculate the tempo and the duration of audio effects like delay and LFO. The calculator...
The BPM (beats-per-minute) calculator was up for an update. The calculator is used to calculate the tempo and the duration of audio effects like delay and LFO. The calculator...
Calculate DCP size from movie length and resolution
To calculate the estimated size of a Digital Cinema Package (DCP) for cinema projection, you need to consider the image size and movie length. The DCP size is primarily determined...
To calculate the estimated size of a Digital Cinema Package (DCP) for cinema projection, you need to consider the image size and movie length. The DCP size is primarily determined...
Calculate foot-lambert from screen size, projector lumen
In the projection business, there is a unit for ‘how much light is coming from that screen, actually?’. This is called the foot-Lambert or fL. To calculate foot lamberts (fL)...
In the projection business, there is a unit for ‘how much light is coming from that screen, actually?’. This is called the foot-Lambert or fL. To calculate foot lamberts (fL)...
Video bitrate from image resolution and bit depth
To estimate the video bitrate based on image resolution and framerate, you can use the following formula: Video Bitrate (bits per second) = Image Resolution (pixels) ×...
To estimate the video bitrate based on image resolution and framerate, you can use the following formula: Video Bitrate (bits per second) = Image Resolution (pixels) ×...
