Financial, health, time-zone and unit calculators with China working-day data
Calcgrid offers 533 deterministic calculators for loans, mortgages, compound interest, BMI, running pace, temperature conversion, lunar calendar dates, and China national working days (2024-2026). Muse can search, run calculations and return typed results with formulas and sources.
Try asking Muse: "How much will my monthly mortgage payment be on a $300,000 home with 20% down at 6.5% over 30 years?"
Source: Found in the official MCP Registry (com.tttkmbb/calcgrid) · First listed September 25, 2026
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Not in Muse's Connectors list yet, but Muse can still use it. Copy the request below and paste it into Muse. Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
https://tttkmbb.com/mcpNot in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
Calcgrid is a remote MCP server, so any assistant that can add a custom connector by link can use it. Same link, same tools.
In ChatGPT, open Settings, then Connectors (called Apps & Connectors on some accounts).
Under Advanced settings, switch on Developer mode. That is what lets you add a connector by link.
Choose Create, give it a name, paste the link as the MCP server URL, and save. If it needs a sign-in, ChatGPT asks for it here.
Start a chat, open the tools menu, pick the connector, and ask. ChatGPT asks before it runs a tool the first time.
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In Claude, open Settings, then Connectors.
Choose Add custom connector, give it a name, and paste the link.
If it needs a sign-in, Claude sends you to it. Then turn the connector on in a chat from the tools menu and ask.
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https://tttkmbb.com/mcpResponse time at the last check: 339ms. Worked in 100% of checks over 30 days.
Screened, no issues found
Screening looks for known threats and hidden instructions at the time of the check, and runs again weekly and whenever the tool list changes. It cannot see the server's code, so only connect what you need and review what Muse asks to do. How screening works.
search_calculatorsUse this when a user needs a deterministic calculation but none of the dedicated tools clearly matches and the calculator_id is unknown. Search 548 calculators from the complete task in English or Chinese, then call run_calculator with the top matching calculator_id and returned list_calculatorsList all calculators, optionally filtered by category id (finance, health, fitness, math, geometry, statistics, conversion, physics, chemistry, everyday, food, construction, business, time, medical, engineering, weather, investing, developer, energy, photography, science, gaming,list_calculator_categoriesList the calculator categories with id, name, description and calculator count. Use it to orient before list_calculators. Does not perform calculations.list_working_day_calendarsUse this before a working-day or business-day task to select the correct evidence package. It distinguishes the worldwide CLDR weekday/weekend baseline, the broad source-labelled OpenWorkdays national-scope reference, the clearly labelled OpenHolidays nationwide public-holiday reget_calculator_schemaUse this only after search_calculators when its input_hints do not resolve a range, enum or optional-field question. Return the full input/output schema, formula, sources, examples and limitations for one calculator. Do not call it when the search result already supplies enough irun_calculatorUse this when the user needs one of Calcgrid's 548 deterministic calculators and no dedicated typed tool covers it. Call it immediately after search_calculators once calculator_id and input_hints are known; do not stop at search or schema discovery. Do not use it for trivial aritconvert_unitsUse this when the user asks to convert a numeric value between units of the same physical quantity: length, mass, temperature, area, volume, speed, time, data, energy, pressure, power, angle, fuel economy, force, frequency, density or torque. Unit symbols and common names are acclist_unitsList every unit symbol supported by convert_units, grouped by quantity, with names. Use it when a unit symbol is rejected with UNKNOWN_UNIT. Does not convert anything.calculate_business_deadlineUse this when you need an SLA, support, procurement or order deadline measured in business hours under the published mainland China or UK calendar, and must express the result in another team's IANA time zone with reproducible holiday and DST evidence. Call this tool directly andcheck_china_working_dayUse this when you need to know whether a specific 2024-2026 date is a working day in mainland China, especially around Spring Festival, National Day or another adjusted holiday. Call this tool directly and return its calculation instead of answering the formula from memory or stoadd_china_working_daysUse this when you need a deadline or settlement date a stated number of mainland China national working days before or after a 2024-2026 date. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use thiscount_china_working_daysUse this when you need the number of official mainland China working days in a 2024-2026 date range for an SLA, payroll, project or delivery estimate. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not check_uk_working_dayUse this when you need to know whether a 2024-2028 UK date is a Monday-Friday working day after applying the official bank holidays for the selected division. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery.add_uk_working_daysUse this when you need a deadline a stated number of UK working days before or after a 2024-2028 date and the correct division's bank holidays matter. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not count_uk_working_daysUse this when you need a 2024-2028 UK SLA, payroll, project or delivery-day count and the selected division's bank holidays must be excluded. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this check_global_working_dayUse this when you need a worldwide weekday/weekend check and have a CLDR alpha-2 territory code, but do not need public-holiday exclusions. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this whadd_global_working_daysUse this when you need a weekday-based date offset for a territory and explicitly want public holidays excluded from the calculation. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when a pcount_global_working_daysUse this when you need a worldwide weekday-based count for a stated territory and public holidays are intentionally outside scope. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when the coconvert_solar_to_lunarUse this when you need the Chinese lunar date, ganzhi day/month/year, zodiac year or current solar term for a given Gregorian date (defaults to today). Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do notconvert_lunar_to_solarUse this when you know a lunar date such as 八月十五 or 闰六月初一 of a given lunar year and need the Gregorian date (e.g. for a lunar birthday or festival). Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not uslist_solar_termsUse this when you need the date or time of 立春, 清明, 夏至, 冬至 or any other solar term in a given year, or the full 24-term table. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when you only neresolve_local_timeUse this when you must safely turn a named-zone local time into an instant, validate a scheduled time around a daylight-saving transition, or preserve every possible interpretation instead of silently choosing one. Call this tool directly and return its calculation instead of anslist_time_zone_transitionsUse this when you need the next or historical daylight-saving/offset changes for scheduling, payroll, travel, audits or a regression test, with a specific reproducible tzdb version. Call this tool directly and return its calculation instead of answering the formula from memory orconvert_time_zoneUse this when you need to know what time an event scheduled in one city corresponds to in another city or in UTC on a specific date. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when you calculate_loan_paymentUse this when you need the monthly payment or total interest cost of an auto, personal, student or other fixed-rate installment loan given its amount, APR and term. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at disccompare_loansUse this when you have two loan or mortgage quotes with different rates, terms or fees for the same amount and want the payments and lifetime costs side by side. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovecheck_global_public_holiday_working_dayUse this when you need a source-labelled 2026-2028 public-holiday reference for one of the supported OpenHolidays countries and nationwide-only semantics are acceptable. Call this tool directly and return its calculation instead of answering the formula from memory or stopping atadd_global_public_holiday_working_daysUse this when you need a 2026-2028 date offset and accept the OpenHolidays nationwide-only, no-inferred-substitute-day reference semantics. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this whcount_global_public_holiday_working_daysUse this when you need a source-labelled nationwide public-holiday reference count for a supported country and regional or substitute-day semantics are not required. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discheck_global_reference_working_dayUse this when you need broad 2026-2028 working-day reference coverage and accept national-scope open-derived semantics rather than a direct authority calendar. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discoveryadd_global_reference_working_daysUse this when you need a broad 2026-2028 date offset and accept OpenWorkdays reference semantics, including its source observed/estimated flags. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use thcount_global_reference_working_daysUse this when you need a broad national-scope reference count and regional or employer semantics are not required. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when the range needs a direcalculate_compound_interestUse this when you need to project a savings account, certificate of deposit or investment balance from a starting amount, an annual rate, a term and optional monthly deposits. Call this tool directly and return its calculation instead of answering the formula from memory or stoppcalculate_mortgage_paymentUse this when you want the monthly cost of buying a home with a fixed-rate mortgage, including escrowed taxes and insurance, or the total interest over the loan. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovecalculate_tipUse this when you need to add a gratuity to a restaurant, delivery or service bill and optionally divide the total among several people. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when calculate_amortization_scheduleUse this when you need to see how each payment splits into principal and interest over the life of a mortgage or loan, the balance at the end of each year, or the effect of paying extra every month. Call this tool directly and return its calculation instead of answering the formucalculate_bmiUse this when you need an adult's BMI, its WHO/CDC weight category, or the weight range that corresponds to a normal BMI (18.5–24.9) for a given height. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do nocalculate_bmrUse this when you need resting daily calorie needs for an adult from sex, weight, height and age, as a base for diet or TDEE calculations. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this whecalculate_tdeeUse this when you need daily maintenance calories for an adult, or calorie targets for a mild/standard deficit or surplus. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when the person is calculate_running_paceUse this when you know a distance and the time it took (or a target time) and need the pace, the equivalent speed, or the time that pace gives over standard race distances. Call this tool directly and return its calculation instead of answering the formula from memory or stoppinghttps://tttkmbb.com/mcpNot in Muse's Connectors list yet, but Muse can still use it. Paste this into Muse: "Use Calcgrid to help me. It is a free service with an MCP server at https://tttkmbb.com/mcp. It does not need an API key. Ask me before you share anything with it." Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
At the last check (November 13, 2026, 12:45 UTC) the endpoint was working, answering in 339ms. Over the last 7 days it answered 100% of health checks. It is checked every 15 minutes.
It was screened on September 25, 2026 with the result "screened, no issues found". Screening checks the domain against threat feeds and reads the tools for hidden instructions and requests for passwords or card numbers. It cannot see the server's code, so grant only the access you need.
It exposes 40 tools, including search_calculators, list_calculators, list_calculator_categories, list_working_day_calendars. For example, you could ask Muse: "How much will my monthly mortgage payment be on a $300,000 home with 20% down at 6.5% over 30 years?"
This listing was added from public sources (Found in the official MCP Registry (com.tttkmbb/calcgrid)). If you build Calcgrid, claim it to correct the details and get your badge.
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