Screen Resolutions Explained: 1080p, 1440p, 4K
What 1080p, 1440p, and 4K really mean. Learn how resolution counts pixels, why total pixels grow so fast, and how aspect ratio ties width to height.
Daniel Okonkwo · 4 min read
Guides & tutorials
Practical guides, how-tos and comparisons to get the most out of our free online tools.
February 3, 2026
How to Adjust Cooking Time for Weight and Temperature
Scale roasting time to the weight of your joint and adjust for oven temperature, so a bigger or smaller cut comes out cooked through but never dry.
Marco Bianchi · 4 min read
February 2, 2026
Rent Affordability: The 30 Percent Rule and Where It Breaks
Thirty percent of gross income leaves $6,800 a month at one income and minus $200 at another. The rule is a fixed percentage applied to a budget whose other needs are not proportional to income — which is exactly why housing policy uses residual income instead.
Camille Laurent · 15 min read
What Is Bitrate? Bits per Second, CBR vs VBR
Bitrate is how many bits of data a video or audio stream uses each second. Learn how it sets quality and file size, and the difference between constant and variable bitrate.
Daniel Okonkwo · 4 min read
How Many Days Have I Been Alive? Count Days, Weeks and Months
Your age in days is the whole number of days between your birth date and today. Learn how to count it by hand, convert it to weeks and months, and why leap years matter.
Lena Hoffmann · 5 min read
Your Flight's Carbon Footprint, Explained
How much CO₂ does a flight emit? Learn the per-passenger-kilometre figures, why short hops are worst per mile, and what the numbers really mean.
Marco Bianchi · 2 min read
January 30, 2026
Retail Markup and Keystone Pricing: How to Set Your Price
Learn how retail markup works, why keystone pricing doubles cost, and the crucial difference between markup and margin — so you set prices that actually cover your costs.
Daniel Okonkwo · 4 min read
How to Round Numbers: Round Half Up, Round Half to Even, and More
Round to any decimal place or number of significant figures, and learn when to use round half up versus round half to even to avoid bias.
Lena Hoffmann · 4 min read
How to Budget on an Irregular Income
A practical method for freelancers and commission earners: baseline on your lowest month, run a buffer account, and pay yourself a steady salary.
Camille Laurent · 4 min read
January 29, 2026
How to Calculate Batting Average and What .300 Means
Batting average is hits divided by at-bats. Learn how to calculate it, why a .300 hitter is excellent and what counts as an at-bat in baseball.
Aisha Karim · 4 min read
January 28, 2026
Countdown to New Year: How to Count the Days and Weeks Left
Building a countdown to a target date is just counting whole days from today to the target, then splitting that total into weeks. Learn the method with a worked example.
Lena Hoffmann · 4 min read
How Many Units Are in a Drink?
A drink's alcohol content depends on its strength (ABV) and volume. Learn how standard drinks and units are calculated and how to count yours.
Sofia Nunes · 3 min read