free web tools & calculators

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.

How could you use these tools?

This motor cycle does 185 km/h. What is that in miles/hr, and in meter/sec?
Click on calculate >> speed
Fill in 180 km/hr. This translates to 115 miles/hr, and 51.39 meter/sec.
Click here for more examples

Data tools

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

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

Cloud Storage Cost
Calculate storage cost for AWS, Google, Azure ...

Electrical power calculator
Volt x Amp → Watt, kWh, Ah, Joule, calorie

Bash boilerplate generator
Deliberate practice according to Malcolm Gladwell

Color tools

RGB color conversion

CMYK color conversion

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

Image filesizes
Image W x H → bytes

Megapixel Aspects
See megapixels 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 → 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 common video bitrates (Prores, DV, DCP, MPEG...)

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

Screen size calculator
Calculate screen size from diagional and aspect ratio

Audio file size calculator
Estimate audio file size for (un)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 of a song or a heartbeat

Web tools

HTML encoder
Encode text full of àççéñts

HTML char map
View all special HTML/Unicode characters

Web Speed/SEO Performance Checks
Check your site on 10+ performance test sites

HTTPS readiness check
Is your site correctly configured for HTTPS?

Calculator tools

Speed converter
m/s ⇆ km/h, mph, mach

Acceleration calculator
Convert m/s² into in/s², g

Distance calculator
Speed x time → distance

Mortgage loan calculator
Calculate monthly payments for a mortgage loan

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

Electric Car calculator
How much $ does your electric car use in kWh per year?

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!

Development blog
Progress on the technical side

Terms & Conditions
Terms & conditions

Privacy Statement
Privacy statement (GDPR compliant)

How to show your appreciation