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ToolSelf Blog

Guides on taxes, finance, business, and practical tools for freelancers and everyone.

Business

10 Free Online Tools Every Small Business Owner Should Bookmark

A curated list of free calculators and converters that save real time when you run a business solo.

Feb 1, 2026
Design

CSS Gradients: Linear vs Radial vs Conic Explained

Three gradient functions in CSS, three completely different effects. Plus the syntax tricks that actually look professional.

Jan 31, 2026
Developer

Base64 vs Hex vs URL Encoding: When to Use Which

Three encodings, three purposes. Picking the wrong one bloats payloads or breaks parsing.

Jan 27, 2026
Finance

Compound Interest: How Your Money Grows Over Time

Einstein called compound interest the eighth wonder of the world. Even small investments can become substantial given time.

Jan 26, 2026
PDF

How to Compress PDFs Without Losing Quality

Most PDF bloat comes from over-sampled embedded images. Smart compression resamples those without touching the text layer.

Jan 25, 2026
Business

SaaS Pricing Models: How to Price Your Subscription

Flat-rate vs tiered vs usage-based pricing. Which model works best for your SaaS product? Here's how to decide.

Jan 24, 2026
Real Estate

PITI: The 4 Things Inside Your Mortgage Payment

Principal, Interest, Taxes, Insurance — and PMI and HOA if applicable. Most buyers underestimate the last three.

Jan 23, 2026
Business

Handling Client Disputes: Payment Terms & Late Invoices

Not all clients pay on time. Here's how to set clear terms upfront, follow up professionally, and handle non-payment.

Jan 22, 2026
Business

Customer Acquisition Cost: How Much Does a Customer Cost?

CAC tells you how much you're spending on marketing to gain each customer. If CAC is too high, your business model breaks.

Jan 19, 2026
Freelance

Time Tracking: Billable Hours & Timesheet Best Practices

Accurate time tracking is essential for billing clients correctly. Here's how to track billable hours and avoid disputes.

Jan 15, 2026
Business

Cash Flow Management: Don't Run Out of Money

Profit ≠ cash. You can be profitable but run out of money if you don't manage cash flow. Here's how to stay solvent.

Jan 13, 2026
Math

Fibonacci Sequence: From Rabbits to the Golden Ratio

Each term is the sum of the previous two. The ratio of consecutive terms converges on phi — the golden ratio.

Jan 8, 2026