// PRACTICAL KNOWLEDGE BASE

USEFUL ANSWERS.
ZERO FLUFF.

One hundred human-readable guides that explain the ideas behind our tools and help you make better everyday decisions.

Showing 100 of 100 practical guides

QR codes001

How to Create a QR Code for a Website

A website QR code is useful when someone sees a printed item but needs to continue online.

4 MIN READ
QR codes002

What Size Should a QR Code Be for Printing?

Print size depends on scanning distance, detail and the quality of the finished material.

4 MIN READ
QR codes003

Using QR Codes on Business Cards

A business-card QR code can reduce typing and direct a new contact to one clear next step.

4 MIN READ
QR codes004

How to Share Wi-Fi Details with a QR Code

A Wi-Fi QR code can help guests join a network without manually typing a long password.

4 MIN READ
QR codes005

Practical QR Codes for Event Information

Event codes work best when they solve a single task such as opening directions, a schedule or a digital ticket.

4 MIN READ
QR codes006

QR Code Accessibility: A Practical Checklist

QR codes should complement accessible information rather than become the only way to reach it.

4 MIN READ
QR codes007

Static vs Dynamic QR Codes Explained

Static codes contain the final information; dynamic services usually redirect through a changeable tracked link.

4 MIN READ
QR codes008

QR Code Error Correction in Plain English

Error correction helps a code remain readable when a small part is damaged, but it does not rescue poor placement.

4 MIN READ
QR codes009

How to Test a QR Code Before Printing

A short test routine prevents an incorrect destination from being reproduced hundreds of times.

4 MIN READ
QR codes010

How to Make a Privacy-Friendly QR Code

A direct static code can work without collecting scan locations, device identifiers or personal profiles.

4 MIN READ
Unit conversion011

How to Convert Metres to Feet

Metres and feet are both length units, but they belong to different measurement systems.

4 MIN READ
Unit conversion012

How to Convert Kilometres to Miles

Converting road or running distances helps compare metric routes with mile-based targets.

4 MIN READ
Unit conversion013

How to Convert Kilograms to Pounds

Kilograms measure mass in the metric system while pounds are commonly used in UK everyday contexts.

4 MIN READ
Unit conversion014

Converting Grams to Ounces for Cooking

Recipe conversions need enough precision to preserve proportions without making kitchen measurements impractical.

4 MIN READ
Unit conversion015

How to Convert Centimetres to Inches

Centimetres and inches often meet in clothing, screen and furniture specifications.

4 MIN READ
Unit conversion016

Miles to Kilometres for Travel Planning

A distance conversion can make foreign road signs and itinerary estimates easier to interpret.

4 MIN READ
Unit conversion017

Metric and Imperial Units: A Quick Guide

Knowing which family a unit belongs to makes it easier to choose the correct conversion.

4 MIN READ
Unit conversion018

Rounding Converted Measurements Sensibly

A converted answer should not imply more accuracy than the original measurement provides.

4 MIN READ
Unit conversion019

How to Check a Unit Conversion

A rough size check catches many inverted conversion factors and misplaced decimal points.

4 MIN READ
Unit conversion020

Unit Conversion for Online Shopping

International listings often use unfamiliar dimensions, weights or capacities.

4 MIN READ
Percentages021

How to Calculate a Percentage of a Number

Finding a percentage of a number is useful for discounts, budgets and proportions.

4 MIN READ
Percentages022

How to Calculate Percentage Increase

Percentage increase compares the size of a rise with the starting value.

4 MIN READ
Percentages023

How to Calculate Percentage Decrease

Percentage decrease shows how large a reduction is relative to where it started.

4 MIN READ
Percentages024

How to Work Out a Sale Discount

A discount percentage tells you the reduction, not automatically the final price.

4 MIN READ
Percentages025

Percentage Points vs Percent Change

Percentage points describe the direct gap between percentages; percent change compares that gap with the starting percentage.

4 MIN READ
Percentages026

Reverse Percentages: Finding the Original Value

Reverse percentages recover a starting value after a known increase or decrease.

4 MIN READ
Percentages027

Using Percentages in a Household Budget

Budget percentages provide a quick view of where income is committed.

4 MIN READ
Percentages028

Percentage Difference Explained

Percentage difference compares two values when neither is naturally the original baseline.

4 MIN READ
Percentages029

How to Calculate an Exam Score Percentage

A score percentage compares marks earned with the total marks available.

4 MIN READ
Percentages030

VAT Percentage Calculations: UK Basics

VAT calculations distinguish between adding tax to a net amount and finding tax already included in a gross amount.

4 MIN READ
BMI and healthy measurement031

How Is BMI Calculated?

BMI divides weight in kilograms by height in metres squared.

4 MIN READ
BMI and healthy measurement032

Understanding Adult BMI Ranges

Reference ranges group BMI values, but the number does not directly measure body fat or fitness.

4 MIN READ
BMI and healthy measurement033

The Important Limitations of BMI

BMI is popular because it is simple, not because it captures every dimension of health.

4 MIN READ
BMI and healthy measurement034

BMI vs Body-Fat Percentage

BMI uses height and weight, while body-fat estimates attempt to describe tissue composition.

4 MIN READ
BMI and healthy measurement035

How Muscle Mass Can Affect BMI

Because BMI does not distinguish muscle from fat, strength-trained people can be placed in a higher category.

4 MIN READ
BMI and healthy measurement036

Measuring Height and Weight for a BMI Estimate

Small measurement errors can noticeably shift a result when someone is near a category boundary.

4 MIN READ
BMI and healthy measurement037

Why Children Need Age-Specific BMI Assessment

Children's BMI is interpreted using age- and sex-related growth references, not the simple adult categories.

4 MIN READ
BMI and healthy measurement038

Why Standard BMI Is Limited During Pregnancy

Pregnancy changes body weight and composition in ways the ordinary BMI formula cannot interpret.

4 MIN READ
BMI and healthy measurement039

Using BMI with Waist Measurement

Waist size can add information about central fat distribution that BMI alone misses.

4 MIN READ
BMI and healthy measurement040

What to Do After Checking Your BMI

A BMI result is a starting point for reflection, not a verdict.

4 MIN READ
Carbon footprint041

How to Estimate Your Personal Carbon Footprint

A useful estimate starts with a few large categories instead of demanding perfect data.

4 MIN READ
Carbon footprint042

Estimating Carbon Emissions from Car Travel

Vehicle emissions depend on distance, fuel, efficiency, occupancy and how the car is used.

4 MIN READ
Carbon footprint043

Understanding the Carbon Impact of Home Electricity

Electricity emissions vary with grid generation and the time period represented by the factor.

4 MIN READ
Carbon footprint044

Why Flight Carbon Estimates Vary

Flight length, aircraft, seating, occupancy, routing and high-altitude effects can change an estimate.

4 MIN READ
Carbon footprint045

Where to Start Reducing a Household Carbon Footprint

The strongest actions depend on which activities dominate the household estimate.

4 MIN READ
Carbon footprint046

What Does CO₂e Mean?

Carbon dioxide equivalent expresses different greenhouse gases using a shared warming-impact unit.

4 MIN READ
Carbon footprint047

Scope 1, 2 and 3 Emissions in Plain English

The scopes organise business emissions into direct fuel use, purchased energy and wider value-chain activities.

4 MIN READ
Carbon footprint048

Carbon Offsets: Questions to Ask

Offsets vary in additionality, permanence, verification and wider community impact.

4 MIN READ
Carbon footprint049

Comparing Lower-Carbon Commuting Options

Distance, occupancy and local infrastructure shape the best practical choice.

4 MIN READ
Carbon footprint050

How to Track a Carbon Footprint Over Time

Consistent boundaries matter more than false precision when monitoring progress.

4 MIN READ
Energy use and cost051

How to Calculate an Appliance's Running Cost

A basic cost estimate combines appliance power, time and electricity price.

4 MIN READ
Energy use and cost052

Watts, Kilowatts and kWh Explained

Watts describe power at a moment, while kilowatt-hours describe energy used over time.

4 MIN READ
Energy use and cost053

How Much Does an Electric Heater Cost to Run?

Electric resistance heaters usually convert electricity to room heat efficiently at the device, but cost depends on power and duration.

4 MIN READ
Energy use and cost054

Estimating Washing Machine Energy Costs

Cycle temperature, load, programme and machine efficiency affect consumption.

4 MIN READ
Energy use and cost055

Understanding Tumble Dryer Running Costs

Dryer technology, load moisture and programme length create large differences in energy use.

4 MIN READ
Energy use and cost056

How to Estimate Computer Energy Use

Computer power changes with workload, display settings and attached equipment.

4 MIN READ
Energy use and cost057

Does Standby Power Matter?

A small continuous load can accumulate over a full year, especially across many devices.

4 MIN READ
Energy use and cost058

Comparing LED Lighting Energy Costs

Lighting cost depends on lamp power, number of lamps and hours used.

4 MIN READ
Energy use and cost059

Smart Meter vs Plug-In Energy Monitor

A smart meter shows whole-property use while a plug monitor isolates a compatible appliance.

4 MIN READ
Energy use and cost060

How to Read Energy Cost Inputs from a UK Bill

A bill separates unit rates, consumption, standing charges and taxes.

4 MIN READ
Dates and time061

How to Calculate Days Between Two Dates

The day difference measures elapsed time from one calendar date to another.

4 MIN READ
Dates and time062

Inclusive vs Exclusive Date Counting

Inclusive counting treats boundary dates as counted days; elapsed-time counting usually measures the gaps between them.

4 MIN READ
Dates and time063

Counting Working Days Between Dates

Working-day calculations remove weekends and may also need regional bank holidays.

4 MIN READ
Dates and time064

How Leap Years Affect Date Differences

Leap years add 29 February, changing totals for periods that cross it.

4 MIN READ
Dates and time065

Converting a Date Difference into Weeks

Exact days divided by seven gives elapsed weeks, while calendar weeks may be counted differently.

4 MIN READ
Dates and time066

Date Counting for Project Deadlines

Clear deadline language prevents disagreement about when work is due.

4 MIN READ
Dates and time067

How Age in Days Is Calculated

Age in days counts elapsed calendar boundaries from the birth date to the reference date.

4 MIN READ
Dates and time068

UK and US Date Formats: Avoiding Confusion

Numeric dates can swap the month and day depending on regional convention.

4 MIN READ
Dates and time069

Time Zones and Date Boundaries

The same instant can fall on different calendar dates in different places.

4 MIN READ
Dates and time070

Monthly Date Rules for Short Months

A recurring date on the 29th, 30th or 31st needs an explicit rule when a month is shorter.

4 MIN READ
Password security071

How to Create a Strong Password

A strong password is long, unique and difficult for another person or program to predict.

4 MIN READ
Password security072

Password Length vs Complexity

Length expands the search space, while predictable complexity rules can lead people to repeat familiar patterns.

4 MIN READ
Password security073

Why Every Account Needs a Unique Password

When one service is breached, reused credentials can be tried automatically on other services.

4 MIN READ
Password security074

Password Managers: A Beginner's Guide

A password manager stores encrypted credentials and can generate a different random password for each account.

4 MIN READ
Password security075

How to Build a Safer Passphrase

A passphrase uses multiple words to create length, but common quotes and obvious sequences remain guessable.

4 MIN READ
Password security076

Two-Factor Authentication Explained

A second factor reduces the damage if a password is stolen, although methods differ in phishing resistance.

4 MIN READ
Password security077

What to Do If a Password Is Exposed

Fast, ordered action can contain the risk from a breached credential.

4 MIN READ
Password security078

What a Password Strength Meter Can and Cannot Tell You

A meter checks visible patterns and length but cannot know every leak, reuse or personal clue.

4 MIN READ
Password security079

How to Secure Account Recovery

Recovery email, phone and backup codes can bypass an otherwise strong password.

4 MIN READ
Password security080

Login Habits That Reduce Phishing Risk

Attackers often steal credentials by imitating trusted sign-in pages.

4 MIN READ
Writing and text metrics081

How to Count Words in a Piece of Text

Word counts help manage assignments, forms, speeches and editorial limits.

4 MIN READ
Writing and text metrics082

Character Count with and Without Spaces

Character limits may include letters, punctuation, symbols and sometimes spaces.

4 MIN READ
Writing and text metrics083

How Estimated Reading Time Works

Reading time usually divides word count by an assumed reading speed.

4 MIN READ
Writing and text metrics084

Using Sentence Length to Improve Clarity

A mix of sentence lengths creates rhythm while preventing complex ideas from becoming tangled.

4 MIN READ
Writing and text metrics085

How to Write Clearer Online Instructions

Effective instructions use an explicit goal, ordered actions and visible outcomes.

4 MIN READ
Writing and text metrics086

How Long Should Website Copy Be?

There is no universal ideal length; the copy should answer the visitor's real questions without padding.

4 MIN READ
Writing and text metrics087

How to Find Repetition in Your Writing

Repeated words and ideas can signal either useful emphasis or unnecessary duplication.

4 MIN READ
Writing and text metrics088

A Practical Plain-English Checklist

Plain English helps readers act by using familiar words, direct structure and appropriate detail.

4 MIN READ
Writing and text metrics089

Estimating Speaking Time from a Script

Speaking is usually slower than silent reading and varies with pauses, demonstrations and audience reaction.

4 MIN READ
Writing and text metrics090

Using Text Metrics for More Accessible Content

Metrics can flag dense material, but accessibility also needs structure, contrast, alternatives and understandable language.

4 MIN READ
Colour and accessibility091

HEX Colour Codes Explained

A six-digit HEX code stores red, green and blue channel values using hexadecimal notation.

4 MIN READ
Colour and accessibility092

RGB Colour Values Explained

RGB describes a colour using red, green and blue light values commonly ranging from 0 to 255.

4 MIN READ
Colour and accessibility093

HSL Colour Format: A Practical Guide

HSL organises colour by hue, saturation and lightness, which can feel intuitive when making related variations.

4 MIN READ
Colour and accessibility094

How to Convert HEX to RGB

Each pair of HEX digits corresponds to one RGB channel.

4 MIN READ
Colour and accessibility095

Web Colour Contrast Basics

Contrast helps people distinguish text and interface elements from their backgrounds.

4 MIN READ
Colour and accessibility096

Choosing Accessible Link Colours

Links need to be identifiable in context, including for people who do not perceive colour differences clearly.

4 MIN READ
Colour and accessibility097

Colour-Blind-Friendly Chart Design

Charts should encode differences using labels, shapes or patterns as well as hue.

4 MIN READ
Colour and accessibility098

How to Build a Practical Web Colour Palette

A useful palette includes roles for surfaces, text, borders, actions, feedback and interactive states.

4 MIN READ
Colour and accessibility099

Why Screen and Print Colours Differ

Screens emit RGB light while most printing uses inks and a different reproducible colour range.

4 MIN READ
Colour and accessibility100

Dark Mode Colour and Contrast

Dark mode is more than reversing black and white; bright colours can vibrate and shadows behave differently.

4 MIN READ