free web tools

This website contains a bunch of web-based tools (you don't need to install anything, just run them here) that I have developed through the years. Use them like you want (within reason) and if you really like them, let me know.



I can write to my USB stick at 13 MB/s. So how much can I write in 15 minutes?
Click on data >> filesize
Fill in 13 MB/s and 15 minutes. This will give you 11.7 GB in those 15 minutes.
If I borrow $20.000 to buy a car, and I pay that off in 4 years, how much do I pay per month?
Click on finance >> mortgage
Fill in 20000 $, 4 years and the current interest rate, e.g. 1.9%. This gives a monthly payment of $433 (FRM).
Click here for more examples

Data tools

Bandwidth converter
Mbps ⇆ KB/s, GB/day, ...

Data size calculator
Calculate 10 Mbps x 6.5 hours = ? GB

Electrical power calculator
Calculate Volt x Ampere = Watt, kWh, Ah, Joule

Network tools

HTTPS readiness check
Is your site ready for Google's HTTPS everywhere policy?

Color tools

RGB color conversion
RGB color ⇆ CMYK, HSV, XYZ, Grayscale...

CMYK color conversion
CMYK color ⇆ RGB, HSV, XYZ, Grayscale...

HTML Color list
List of named HTML colors

Pantone Color list
List of named Pantone colors

Websafe Color list
List of websafe colors

Photo tools

Aspect ratio calculator
Image W x H → aspect ratio

Megapixel calculator
Image W x H → megapixels

Megapixel Aspect Comparison
See megapixel in different aspect ratios

DPI calculator
Print W x H and dpi → megapixels

Composition calculator
Focal length, subject distance, crop factor → image composition

Depth-of-Field calculator
Aperture, focal length, subject distance, crop factor → depth-of-field

Light calculator (EV)
Aperture, shutter time, ISO => Exposure Value

Video tools

Frame rate converter
Framerate conversion with ffmpeg and sox

Video bitrate calculator
Estimate video bitrate based on resolution, fps and bit depth

Common video bitrates
List of commong video bitrates

Video file size calculator
Estimate video file size from resolution and duration

Audio file size calculator
Estimate audio file size for uncompressed and compressed audio

DCP file size calculator
Calculate DCP audio and video filesizes

Music tools

Convert BPM to beat, measure and song length

Tap your tempo
Tap to find the BPM

Web tools

HTML encoder
Encode text full of àççéñts

HTML char map
View all special HTML/Unicode characters

Calculator tools

Mortgage loan calculator
Calculate monthly payments for a mortgage loan

Fuel Cost calculator
How much $ does your car fuel cost per year?

Speed converter
Convert m/s into km/h, mph, mach

Distance calculator
Speed x time → distance

Gladwell's 10000 hour-rule
Deliberate practice according to Malcolm Gladwell

About tools

Examples of how to use the tools
Show me how I can use these tools

History & development
What? Who? Why? How?

Remarks about this site? Let me know!

Terms & Conditions
Terms & conditions, privacy statement

How to show your appreciation

Development blog
Progress on the technical side