Guides
Every calculator on Quikbench gives you a number. These guides exist for the question that usually comes right after: why is the number what it is, and what mistake would have gotten it wrong? Each one works through a real, worked example rather than just restating a formula — the kind of explanation we wanted when we were trying to figure this stuff out ourselves.
Loans & borrowing
EMI vs. Flat Rate Interest: Why the Same Loan Can Cost You Two Different Amounts
A worked example showing why an "8% flat rate" loan can end up costing as much as a 14–15% reducing-balance loan, and how to spot which one a lender is actually quoting you.
Investing & retirement
SIP vs. Lump Sum: What the Math Actually Says
A month-by-month unit-price calculation showing exactly when rupee-cost averaging helps, when it hurts, and why the "right" answer depends on where the market goes after you invest.
Compound Interest Explained: Frequency, Time, and the Real Math
Why the same annual rate can produce different returns depending on how often it compounds, and why the ten years before you start investing matter more than the rate you chase.
How Much You Actually Need to Retire: A Step-by-Step Corpus Calculation
A practical method for sizing your retirement corpus from today's expenses, projected inflation, and the 25x rule — then working backward to the monthly SIP that gets you there.
Tax & GST/VAT
Understanding GST Slabs in India: A Practical Guide for Freelancers
CGST vs SGST vs IGST, explained with a real invoice example, plus how input tax credit means what you owe is usually less than your invoice's headline GST figure.
UK VAT for Freelancers: Registration, Rates, and Invoicing Explained
When you actually need to register for VAT, the difference between zero-rated and exempt (they're not the same), and how to add or extract VAT without the common arithmetic mistake.
Creators & social media
YouTube CPM vs RPM: Why Your Payout Is Never What CPM Suggests
The real difference between CPM and RPM, why your actual payout is always lower than the CPM number on your dashboard, and what actually moves both metrics.
Instagram Engagement Rate: What Counts as Good, By Account Size
How to calculate engagement rate correctly, why it naturally falls as an account grows, and rough benchmarks so you're not judging a 5,000-follower account against a celebrity's numbers.
Files & formats
JPG vs PNG vs WEBP: How to Actually Choose an Image Format
A practical decision guide based on what the image actually is — a photo, a logo, a screenshot — rather than defaulting to whatever format your camera or design tool happened to save.
More on the way
We're adding new guides regularly, covering the reasoning behind the other calculators and tools on Quikbench. If there's a topic you'd like covered, get in touch and tell us what you're trying to work out.