Calculators

TextGround's calculators cover two distinct domains: AI infrastructure planning (how much context does my agent need? what will this LLM usage cost?) and personal finance (mortgage payments, investment growth, FIRE planning). Every calculator runs in your browser and shows its assumptions and formula alongside the result.

Finance calculators are for estimation and education only — outputs are not financial advice. Check the assumptions each calculator displays before relying on a number for a real decision.

AI & LLM calculators Finance calculators All local Not financial advice

AI & LLM Calculators

AI Agent Memory Calculator

Plan token budget across system prompt, tools, history, and RAG for 8K–2M context models.

AI Context Window Visualiser

Compare LLM context window sizes and test whether your text fits.

AI Pricing Calculator

Estimate LLM API costs from input/output tokens and request volume.

Token Counter

Count tokens in any prompt for GPT-4o, Claude 3.5, Gemini, and Llama.

Embedding Similarity

Calculate cosine similarity between text embedding vectors.

RAG Chunk Simulator

Preview how text splits into chunks before embedding — tune size and overlap.

Finance Calculators

Mortgage Calculator

Monthly payment, total interest, and a full amortisation schedule.

Compound Interest Calculator

Project savings growth with regular contributions — year-by-year table.

FIRE Calculator

Estimate years to financial independence and your FIRE number.

Coast FIRE Calculator

Find the savings amount where compounding alone reaches your retirement target.

Investment Fee Calculator

See how expense ratios erode returns over decades.

Roth vs Traditional Calculator

Compare after-tax retirement outcomes at your tax rates.

Rent vs Buy Calculator

Compare total costs of renting and buying over your time horizon.

Credit Card Payoff Calculator

See how long a balance takes to clear and test extra payments.

Emergency Fund Calculator

Calculate a target emergency fund from your monthly essentials.

Salary Tax Calculator (US)

Estimate take-home pay after federal, state, FICA, and 401k deductions.

Everyday Utilities

Stopwatch

Full-screen stopwatch with lap times — no download.

Countdown Timer

Large-display countdown with alert at zero.

World Clock

Current time in major cities side by side.

Epoch Converter

Convert Unix timestamps to dates and back — seconds and milliseconds.

QR Code Generator

Create a QR code for any URL — free, no expiry, no sign-up.

Wheel Spinner

Spin a wheel of names or options to pick a random winner.

Random Group Generator

Split a name list into random teams or pairs.

Finance calculators — important note: Results are estimates for educational and planning purposes only. They are not financial advice. Always verify assumptions (tax rates, interest rates, investment returns) against current figures and consult a qualified financial adviser before making significant money decisions.

Frequently Asked Questions

Are the AI pricing figures up to date?

The AI Pricing Calculator uses prices entered by you or pre-loaded at the time of the tool's last update. LLM prices change frequently — always verify against the provider's current pricing page before making budget decisions. The tool page notes the date of its price data.

Are the finance calculators accurate for my country?

Most finance calculators (including the Salary Tax Calculator) model US tax rules. They are intended for estimation and learning — results are not a substitute for a tax professional or financial adviser in your jurisdiction.

Do these tools send my financial data anywhere?

No. All calculations run in your browser. None of the numbers you enter are transmitted to TextGround's servers or to any third party.