{"success":true,"version":"v1","request":{"tool":"list_calculators","category":"everyday"},"result":{"entity_type":"calculator_list","status":"completed","count":20,"calculators":[{"calculator_id":"age","entity_type":"calculator","name":"Age Calculator","category":"everyday","tool_name":"calculate_age","description":"Computes the exact age on a given date as years, months and days by Gregorian calendar arithmetic, plus total days and weeks, the weekday of birth, and the date of and days until the next birthday.","use_when":"You need someone's exact age on a date, the total number of days lived, the weekday they were born on, or how many days remain until their next birthday.","do_not_use_when":"You need the difference between two arbitrary dates with a business-day count (use date-difference) or a countdown to an event (use 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or plug-in meter), or you need to convert energy units (use energy).","required_inputs":["power_watts","hours_per_day","price_per_kwh"],"optional_inputs":["days"],"urls":{"html":"https://tttkmbb.com/everyday/electricity-cost","markdown":"https://tttkmbb.com/everyday/electricity-cost.md","schema":"https://tttkmbb.com/api/v1/calculators/electricity-cost","api":"https://tttkmbb.com/api/v1/calculate/electricity-cost"}},{"calculator_id":"bill-split","entity_type":"calculator","name":"Bill Split Calculator","category":"everyday","tool_name":"calculate_bill_split","description":"Adds an optional tip percentage to a bill and divides the total equally among a number of people, reporting the tip, the total and each person's share.","use_when":"A restaurant bill, taxi fare or shared purchase must be divided equally among several people, with or without a tip.","do_not_use_when":"Shares are unequal (itemised bills), you only need the tip amount for one payer (use tip), or the cost is a trip's fuel (use fuel-cost).","required_inputs":["total_bill","people"],"optional_inputs":["tip_percent"],"urls":{"html":"https://tttkmbb.com/everyday/bill-split","markdown":"https://tttkmbb.com/everyday/bill-split.md","schema":"https://tttkmbb.com/api/v1/calculators/bill-split","api":"https://tttkmbb.com/api/v1/calculate/bill-split"}},{"calculator_id":"unit-price","entity_type":"calculator","name":"Unit Price Comparison Calculator","category":"everyday","tool_name":"calculate_unit_price","description":"Divides each price by its quantity to get the price per unit, tells which of two options is cheaper per unit and by what percentage.","use_when":"You are comparing two package sizes or brands of the same product (e.g. 500 g for 3.49 vs 1 kg for 5.99) and want the better value per unit.","do_not_use_when":"The two quantities are in different units (convert them to the same unit first, e.g. with mass or volume), or you need a discount on a single price (use 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rates (adjust words_per_minute).","required_inputs":["word_count"],"optional_inputs":["words_per_minute"],"urls":{"html":"https://tttkmbb.com/everyday/reading-time","markdown":"https://tttkmbb.com/everyday/reading-time.md","schema":"https://tttkmbb.com/api/v1/calculators/reading-time","api":"https://tttkmbb.com/api/v1/calculate/reading-time"}},{"calculator_id":"typing-speed","entity_type":"calculator","name":"Typing Speed Calculator","category":"everyday","tool_name":"calculate_typing_speed","description":"Computes gross words per minute from characters typed (one word = 5 characters) or from a word count, then net WPM after penalising uncorrected errors, plus accuracy and characters per minute.","use_when":"You timed a typing test and know the characters or words typed, the time and the number of errors, and want standard WPM figures.","do_not_use_when":"You need reading speed (use reading-time) or the test software already reports WPM under its own error 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gpa).","required_inputs":["current_grade_percent","final_weight_percent","desired_grade_percent"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/everyday/final-grade","markdown":"https://tttkmbb.com/everyday/final-grade.md","schema":"https://tttkmbb.com/api/v1/calculators/final-grade","api":"https://tttkmbb.com/api/v1/calculate/final-grade"}},{"calculator_id":"sleep-cycles","entity_type":"calculator","name":"Sleep Cycle Calculator","category":"everyday","tool_name":"calculate_sleep_cycle_times","description":"Suggests bedtimes for a given wake-up time, or wake-up times for a given bedtime, so that sleep ends at the boundary of a full sleep cycle (default 90 minutes) after a typical time to fall asleep (default 14 minutes).","use_when":"You want to pick a bedtime or alarm time that completes 3–6 whole sleep cycles instead of waking mid-cycle.","do_not_use_when":"You have a sleep disorder or shift-work schedule needing clinical advice; cycle length varies between people and 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protocol overhead, server limits and Wi-Fi conditions.","required_inputs":["file_size","speed"],"optional_inputs":["size_unit","speed_unit"],"urls":{"html":"https://tttkmbb.com/everyday/download-time","markdown":"https://tttkmbb.com/everyday/download-time.md","schema":"https://tttkmbb.com/api/v1/calculators/download-time","api":"https://tttkmbb.com/api/v1/calculate/download-time"}},{"calculator_id":"leap-year","entity_type":"calculator","name":"Leap Year Calculator","category":"everyday","tool_name":"classify_leap_year","description":"Applies the Gregorian leap-year rule (divisible by 4, except centuries not divisible by 400) to a year and reports the reason, the number of days in the year and in February, and the next and previous leap years.","use_when":"You need to know whether a year has 29 February, why, or when the next leap year occurs.","do_not_use_when":"You need the weekday or ISO week of a specific date (use day-of-week) or day counts between dates (use date-difference).","required_inputs":["year"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/everyday/leap-year","markdown":"https://tttkmbb.com/everyday/leap-year.md","schema":"https://tttkmbb.com/api/v1/calculators/leap-year","api":"https://tttkmbb.com/api/v1/calculate/leap-year"}},{"calculator_id":"roman-numeral","entity_type":"calculator","name":"Roman Numeral Converter","category":"everyday","tool_name":"convert_roman_numeral","description":"Converts an integer from 1 to 3999 into standard (subtractive-notation) Roman numerals, or parses a Roman numeral back into a number, and shows the value of each symbol group.","use_when":"You need to write a year, chapter or clock number in Roman numerals, or read one such as MCMXCIV.","do_not_use_when":"The number is 0, negative, 4000 or larger, or not an integer (standard Roman numerals cannot express these); for other number systems use base-converter.","required_inputs":["mode","value"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/everyday/roman-numeral","markdown":"https://tttkmbb.com/everyday/roman-numeral.md","schema":"https://tttkmbb.com/api/v1/calculators/roman-numeral","api":"https://tttkmbb.com/api/v1/calculate/roman-numeral"}},{"calculator_id":"work-hours","entity_type":"calculator","name":"Work Hours Calculator","category":"everyday","tool_name":"calculate_work_hours","description":"Derives paid hours per day from shift start and end times minus unpaid breaks, scales them to a week (working days), an average month (52/12 weeks) and a year (52 weeks), and multiplies by an optional hourly rate for pay.","use_when":"You want to know your working hours per week, month or year from a daily schedule, or the pay they represent at an hourly rate.","do_not_use_when":"Shifts vary day by day (sum each with time-duration), or you need salary conversions between periods without shift times (use salary-converter).","required_inputs":["start_time","end_time"],"optional_inputs":["break_minutes","days_per_week","hourly_rate"],"urls":{"html":"https://tttkmbb.com/everyday/work-hours","markdown":"https://tttkmbb.com/everyday/work-hours.md","schema":"https://tttkmbb.com/api/v1/calculators/work-hours","api":"https://tttkmbb.com/api/v1/calculate/work-hours"}}]},"timestamp":"2026-09-23T23:27:19Z","next_actions":[],"links":{"docs":"https://tttkmbb.com/calculators.md"}}