The Lekkal blog

The numbers that run a business, explained simply.

Short, practical guides to the finance concepts founders and freelancers actually hit in the wild — no jargon, no fluff. Every guide pairs with a free calculator so you can run your own numbers as you read.

Margin vs markup: the difference that quietly kills profit

They measure the same profit against different bases — and confusing them means every sale earns less than you think. Here's how to keep them straight.

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How to calculate your break-even point (with examples)

The sales volume where revenue finally covers every cost. Learn the formula, the role of contribution margin, and how to read your margin of safety.

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Burn rate and runway: how long will your cash last?

Gross vs net burn, the runway formula, and why a single growth assumption can swing your "months left" by a year. The number every founder should know cold.

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How much should I charge? A freelance hourly-rate formula

Why dividing your old salary by 2,080 hours leaves money on the table — and the formula that accounts for overhead, taxes, profit, and unbillable time.

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