Business Calculators
The numbers behind pricing, margin and capacity decisions.
Most business arithmetic is simple in isolation and easy to get wrong in practice, usually because two similar-sounding quantities get confused. Margin and markup are the classic pair. Adding tax and removing tax is another. An SLA percentage and the downtime it actually permits is a third.
Each calculator here shows the intermediate figures rather than only the answer, so you can see which number drove the result and sanity-check it against what you expected.
- Profit Margin Calculator Enter cost and selling price to get margin, markup and cost ratio, with the difference made explicit.
- Loan & EMI Calculator Monthly payment, total interest and a first-year schedule showing how little early payments touch the principal.
- Break-even Calculator Work out how many units you must sell before the business stops losing money.
- Sales Tax / VAT / GST Calculator Add tax to a net figure or extract it from a gross one, with both directions shown.
- Percentage Calculator X% of Y, X as a percentage of Y, and percentage change from X to Y.
- ROI Calculator Compare investments on return, payback and annualised terms rather than headline percentage alone.
- Freelance Hourly Rate Calculator Work backwards from target income, expenses, tax and billable hours to the minimum rate that supports them.
The arithmetic behind pricing decisions
These are small calculations that people get wrong in expensive, repeatable ways. Not because the maths is hard, but because two similar-sounding terms mean different things and the difference compounds across every sale.
Each tool here shows its working, because a number without its reasoning is difficult to argue with and easy to misapply.
Margin and markup are not the same number
This one deserves its own section because it costs real businesses real money.
An item costs 60 and sells for 100. The markup is 67% — the amount added to cost. The margin is 40% — the share of the selling price that is profit. Both describe the same transaction. Only one of them tells you whether you can survive a 40% discount.
Price using markup while budgeting on margin and every product looks more profitable than it is. The Profit Margin Calculator shows both figures side by side for exactly this reason.
What the others are for
| You need to know | Tool |
|---|---|
| What to charge, and what the profit actually is | Profit Margin Calculator |
| The monthly payment and true interest cost of a loan | Loan & EMI Calculator |
| How many units before the business stops losing money | Break-even Calculator |
| Tax added to a net price, or extracted from a gross one | Sales Tax Calculator |
| Percentages, in all three directions people confuse | Percentage Calculator |
| Whether an investment beat the alternative | ROI Calculator |
| The minimum hourly rate that supports your income target | Freelance Hourly Rate Calculator |
Two results worth sitting with
Early loan payments barely touch the principal. The EMI calculator shows the first year's schedule, and the split is usually a surprise: most of each early payment is interest. This is what makes overpaying early so disproportionately effective, and why a loan refinanced in year four rarely saves what the headline rate suggests.
Your billable hours are not your working hours. The freelance rate calculator asks for billable hours specifically, and most people's honest figure is around half their working week once admin, sales, invoicing and unpaid revisions are counted. Dividing a target income by 40 hours produces a rate that quietly guarantees a shortfall.
What these do not account for
They are arithmetic, not advice. The margin calculator does not know your competitors, the ROI calculator does not price risk, and the loan calculator ignores arrangement fees and early-repayment penalties that can change which option is cheaper. Use them to get the numbers right, then apply judgement the numbers cannot contain.
Common questions
What is the difference between margin and markup?
Markup is calculated on cost, margin on selling price. An item costing 60 and selling for 100 carries a 67% markup and a 40% margin — the same transaction described two ways. Confusing them is the most common and most expensive pricing error there is, which is why the calculator always shows both.
What is a good profit margin?
It varies enormously by industry, so a universal number would be misleading. Grocery retail survives on low single digits through volume; software can exceed 80%. The useful comparison is against others in your sector and against your own trend, not against a general benchmark.
Why does my loan cost so much more than the amount borrowed?
Because interest is charged on the outstanding balance, and early in the term almost the entire balance is still outstanding. The first-year schedule makes this visible: most of each early payment is interest, not principal. It is also why overpaying in the first years saves disproportionately more than overpaying later.
How do I work out my freelance hourly rate?
Start from target income, add business expenses and tax, then divide by realistically billable hours — not working hours. Most freelancers bill roughly half the hours they work once admin, sales and unpaid revisions are counted. Using total hours produces a rate that cannot reach the target it was calculated from.
Are these calculators accurate enough for real decisions?
The arithmetic is exact. What they cannot include is your specific context: fees, penalties, tax treatment, seasonality and risk. For a significant decision, use these to get the numbers right and then check the assumptions with someone who knows your situation.
Is my data stored when I use a calculator?
No. Figures you enter are used to produce the result and then discarded. Nothing is written anywhere, which matters more here than elsewhere on the site — these inputs describe your business.