Plantrino Guides

Guides & Explainers

Clear, practical articles that explain the numbers behind everyday decisions — from your health to your money. Every guide is written in plain English, with worked examples you can follow.

Health & Body

What Your BMI Really Tells You

How Body Mass Index is calculated, what each category means, and the limits of the number.

Health & Body

How Many Calories Do You Need?

Calculating daily calorie needs from your BMR and activity level — with examples.

Money & Finance

How Loan Repayments Are Calculated

Principal, interest, term, and the formula that ties them together — explained simply.

Money & Finance

Gross vs. Net Pay

Why your contract salary and your bank deposit differ — and how to estimate take-home pay.

Money & Finance

What Determines Your Mortgage Payment

Principal, interest, taxes, insurance, and the levers that move your monthly figure.

Money & Finance

How Income Tax Brackets Work

Why a higher bracket does not tax all your income, and what an effective rate really is.

Money & Finance

Compound Interest Explained

How money grows on itself, the Rule of 72, and why starting early beats starting big.

Money & Finance

How Inflation Shrinks Your Money

What inflation really is, real vs. nominal returns, and what it means for savers.

Money & Finance

Snowball vs. Avalanche Debt Payoff

Two proven ways to clear debt — one is cheapest, one keeps you motivated.

Money & Finance

Rent or Buy?

The real costs on each side, the break-even horizon, and a myth worth retiring.

Everyday Maths

How to Calculate Percentages

The three percentage calculations that cover almost every everyday question.

Business

Markup vs. Margin

Both describe profit — but confusing them quietly costs a business money.

Health & Body

Body Fat Percentage Explained

What it measures, how it is estimated, and the general healthy ranges.

Health & Body

How Much Protein Do You Need?

What protein does, how much different people need, and the myths to ignore.

Health & Body

How Much Water Should You Drink?

Where the "8 glasses" rule came from and a more useful way to gauge hydration.

Health & Body

Macros Explained

Protein, carbs, and fat — what they do and why no single split is "perfect".

Health & Body

Sleep Cycles & Best Wake Time

Why waking between cycles feels better, and how to time your bedtime.

Health & Body

Do You Really Need 10,000 Steps?

The marketing origin of the number, and how to set a step goal that fits you.

Health & Body

TDEE: Your Daily Energy Expenditure

The total calories your body burns — the foundation of any calorie goal.

Tax

How GST Works in Australia

Adding and removing the 10% — and why you divide by 11, not subtract 10%.

Property

Stamp Duty Explained

The big upfront cost of buying a home, and how the sliding scale works.

Tax

Capital Gains Tax Explained

How a gain is calculated, and why CGT is usually part of your income tax.

Tax

Tax Deductions, Properly Understood

Why a deduction saves you your tax rate's share — not the full amount.

Property

First Home Buyer Costs

The deposit is only the start — what else to budget for before you buy.

Property

How Much House Can You Afford?

The bank's maximum is not your real budget. Here is how to find yours.

Investing

Is an Investment Property Worth It?

Rental yield explained — and the gap between the gross and net figures.

Income & Work

How to Read Your Payslip

Every line explained — gross pay, tax, super, deductions, and net pay.

Income & Work

How Overtime Pay Is Calculated

Time-and-a-half, double-time, and penalty rates — made simple.

Income & Work

Hourly and Annual Pay Conversion

Turning a wage into a salary — and why the simple formula can mislead.

Income & Work

How Annual Leave Accrues

Leave builds up gradually as you work — here is how it is paid.

Income & Work

What a Pay Rise Really Adds

Why a raise never arrives in full — and why it cannot leave you worse off.

Income & Work

Setting Your Freelance Rate

Why "salary divided by hours" underprices you — and the better way.

Income & Work

Side Hustle Income Basics

Why the extra money is taxable and stacks on top of your main income.

Savings & Investing

The FIRE Movement Explained

Financial independence, the savings rate, and the 25x rule.

Savings & Investing

Net Worth: Your Financial Scoreboard

Assets minus liabilities — the best single measure of financial health.

Savings & Investing

How to Reach a Savings Goal

Turn any goal into a monthly number — and make the habit stick.

Savings & Investing

Emergency Funds: How Much to Save

The buffer that turns a crisis into an inconvenience — sized for you.

Savings & Investing

Future Value of Your Money

What a sum or regular contributions could grow to — and why time wins.

Savings & Investing

Understanding Investment Returns

ROI, annualised, real, and total return — and what each really means.

Savings & Investing

Dividend Yield Explained

Income from shares — and why a very high yield can be a warning.

Savings & Investing

Superannuation Basics

How retirement savings grow, and why early super is so powerful.

Savings & Investing

How Much Do You Need to Retire?

A clear way to estimate your own retirement number.

Debt

How Credit Card Interest Works

The interest-free period, and why minimum payments are a trap.

Debt

Car Loans Explained

Loan term trade-offs, depreciation, and looking past the monthly payment.

Business

The Break-Even Point

When a business stops losing money and starts to profit.