What can I calculate on Calnexa?

Calnexa has calculators for age, dates, money, AI costs, math, and education, grouped by topic on this page. You can also use the search box at the top to go straight to one.

How are tools grouped on the homepage?

By topic: Age Tools, Date Tools, Money Tools, AI Tools, Math Tools, and Education Tools. Popular Tools at the top is a set of shortcuts, not a separate category.

Why do some tools appear in one language but not another?

Not every calculator is available in every language. The homepage in each language lists only the tools you can use in that language.

Calnexa | Online Calculators

Find online calculators for age, date, money, and percentage tasks

Calnexa organizes online calculators into clear age, date, money, and math clusters, so you can go straight to the tool you need.

Search for a calculator directly, or jump to a cluster below.

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Popular calculators right now

Quick links to calculators for everyday age, date, money, and percentage questions.

Showing 6 tools

Math Tools

Percentage Calculator

Solve percentage, ratio, increase, and decrease questions without spreadsheet friction.

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Date Tools

Date Calculator

Calculate days between dates or add and subtract time from one calendar date.

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Age Tools

Age Calculator

Calculate exact age in years, months, and days from a date of birth.

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Money Tools

Tip Calculator

Work out tip, total bill, and split amount per person with minimal input.

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Money Tools

Discount Calculator

Check sale price, savings, and discount impact for purchase decisions.

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Date Tools

Time Zone Converter

Convert a date and time between regions and compare the real UTC offset difference.

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Age Tools

A focused age cluster covering exact age, age on a specific date, age difference, and next birthday timing.

Age Tools

Age Calculator

Calculate exact age in years, months, and days from a date of birth.

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Age Tools

Age on a Specific Date

See how old someone was or will be on any chosen date.

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Age Tools

Age Difference Calculator

Compare two birth dates and calculate the exact age gap.

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Age Tools

Next Birthday Calculator

Check the next birthday date and the number of days remaining.

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Age Tools

Sibling Age Gap Planner

Enter the first child's birthday and a target age gap to reverse-calculate the second child's conception and birth windows.

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Age Tools

Korean Age Calculator

Calculate your age in all three Korean systems: international age (만 나이), year age (연 나이), and traditional counting age (세는나이). Includes the 2023 reform.

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Date Tools

A date cluster for date math, workday logic, countdown planning, and cross-time-zone conversion.

Date Tools

Date Calculator

Calculate days between dates or add and subtract time from one calendar date.

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Date Tools

Day of Week Calculator

Check what weekday any date falls on, including birthdays, historical dates, and future plans.

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Date Tools

Best Before Date Calculator

Explain how to calculate a best before date and work out the date when the shelf-life rule is already known.

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Date Tools

Time Zone Converter

Convert a date and time between regions and compare the real UTC offset difference.

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Date Tools

Time Difference Calculator

Measure the elapsed time between two date-time moments and review total hours, total minutes, and multi-day duration.

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Date Tools

Business Days Calculator

Count workdays between dates or add business days to a deadline.

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Date Tools

Work Hours Calculator

Calculate hours worked across shifts, subtract unpaid breaks, and total the result in both HH:MM and decimal hours.

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Date Tools

Countdown Calculator

Track how many days remain until a target date or event.

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Money Tools

A payment and bill math cluster for tip, bill splitting, and tax-aware total calculations.

Money Tools

Tip Calculator

Work out tip, total bill, and split amount per person with minimal input.

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Money Tools

Discount Calculator

Check sale price, savings, and discount impact for purchase decisions.

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Money Tools

Split Bill Calculator

Split a bill evenly and see how much each person should pay.

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Money Tools

Tax and Tip Calculator

Calculate the total after tax and tip in one payment flow.

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Money Tools

Child Support Calculator

State-by-state child support calculators built around each state's rules.

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AI Tools

A practical AI cost cluster for comparing LLM pricing assumptions across providers and models.

AI Tools

LLM Cost Calculator

Estimate token-based LLM costs across supported providers and models with current pricing assumptions.

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Math Tools

A practical math cluster for percentages, unit and size conversions, and other everyday calculations.

Math Tools

Percentage Calculator

Solve percentage, ratio, increase, and decrease questions without spreadsheet friction.

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Math Tools

Unit Converter

Convert common units for study, travel, and practical daily math.

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Math Tools

Sleep Calculator

Estimate sleep and wake-up timing around common bedtime patterns.

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Math Tools

Ring Size Converter

Convert ring sizes across 7 international standards in real time. Enter inner diameter, circumference, or a US size number.

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Math Tools

Printable Ring Sizer

Print a finger-wrap strip or ring circle gauge, calibrated against a credit-card-sized frame, and measure your size with a ruler in hand.

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Math Tools

Shoe Size Converter

Convert shoe sizes between US, UK, EU, JP, KR, MX, BR, and CN. Men, women, and kids. Enter any size or foot length (cm).

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Math Tools

Bra Size Converter

Convert bra sizes across US, UK, EU, FR, IT, AU, JP, KR. Includes sister size calculator and accurate US/UK cup divergence from DD onwards.

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Math Tools

Cups to Grams Converter

Convert cups to grams or grams to cups by ingredient — flour, butter, sugar, and 50+ more. King Arthur data, US and metric cup support.

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Math Tools

Clothing Size Converter

Convert women's, men's, and kids' clothing sizes across US, UK, DE, FR, IT, JP, KR, AU. Measure yourself or pick a known size.

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Math Tools

Hat Size Converter

Convert head circumference (cm/inch) to US, UK, and EU hat sizes plus S/M/L/XL letter tiers. Includes a step-by-step measuring guide.

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Math Tools

Glove Size Converter

Convert palm circumference (cm/inch) to fashion, old UK/French, and EN 420 work-glove sizes. Never mixes the three systems.

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Education Tools

A practical education cluster for GPA calculation, weighted grade tracking, and final exam planning.

Education Tools

GPA Calculator

Calculate semester or cumulative GPA with US, Taiwan, Japan, and Korea grading scales.

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Education Tools

Grade Calculator

Calculate your course grade using weighted percentages or points. Supports extra credit.

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Education Tools

Final Grade Calculator

Find out what score you need on your final exam to reach your target grade.

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Built for fast decisions, not software onboarding

Instant use

Start with a search or a single click — no setup and no account prompts.

Lightweight by default

Clean pages with little visual noise that load quickly on any device.

Trustworthy outputs

Each tool explains what it calculates, then shows the result clearly.

Mobile-ready scanning

Tap targets, spacing, and layout are sized for quick use on a phone.

Frequently Asked Questions

What can I calculate on Calnexa?: Calnexa has calculators for age, dates, money, AI costs, math, and education, grouped by topic on this page. You can also use the search box at the top to go straight to one.
How are tools grouped on the homepage?: By topic: Age Tools, Date Tools, Money Tools, AI Tools, Math Tools, and Education Tools. Popular Tools at the top is a set of shortcuts, not a separate category.
Why do some tools appear in one language but not another?: Not every calculator is available in every language. The homepage in each language lists only the tools you can use in that language.