Nanocalcs

Search the 431 free calculators and converters on nanocalcs.com by keyword (any language). Returns id, name, page URL, accepted prefill parameters and an example prefilled URL. Use the id with build_link to give the user a page with their own numbers filled in.

Build a nanocalcs.com URL for a tool id with inputs pre-filled via query parameters. Values are validated against the tool's parameter spec (ranges, allowed values, dates); invalid or unknown parameters are rejected with the accepted list. Give the returned url to the user.

Exact percentage math. mode "of": a% of b. mode "what": a is what % of b. mode "change": percent change from a to b. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Monthly loan repayment, total interest and total paid. type annuity (equal payments, default), principal (equal principal) or bullet (interest-only, principal at the end). The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Add or subtract years, months, weeks and days from a date (month-end clamped: Jan 31 + 1 month = Feb 28/29). The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Number of days, weeks, and years/months/days between two dates. inclusive counts the end date too. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Exact age in years, months and days, total days, and the next birthday. on defaults to today (UTC). The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Convert units with exact definitional factors. Units by category: length: mm, cm, m, km, in, ft, yd, mi, nmi; mass: mg, g, kg, t, oz, lb, st, ton_us, ton_uk; temperature: c, f, k, r; volume: ml, l, m3, tsp, tbsp, floz, cup, pt, qt, gal, pt_uk, gal_uk, in3, ft3; area: cm2, m2, ha, km2, in2, ft2, yd2, ac, mi2; speed: mps, kph, mph, fps, kn; time: ms, s, min, h, d, wk, mo, yr; data: bit, B, kB, MB, GB, TB, KiB, MiB, GiB, TiB, Mbit, Gbit. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Body mass index with WHO adult category and the healthy weight range for the height (metric). The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Total ROI %, profit, multiple, and annualized (compound) return when a period is given. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Exact token count with OpenAI tiktoken encodings (o200k_base default, cl100k_base), plus Claude and Gemini estimates. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Whether a prompt fits each model's context window, with remaining tokens after an output reserve. Give tokens, or text to count with o200k_base. Omit model to check all listed models. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

API cost per request, day, month and year from list prices. Omit model to get the 10 cheapest. Models: gpt-6-astra, gpt-6.1-sol, gpt-6-luna, gpt-5.6-sol, gpt-5.5, gpt-5.4-mini, gpt-5-mini, gpt-4.1, gpt-4o-mini, claude-fable-5.1, claude-opus-5.5, claude-sonnet-5.5, claude-haiku-5.5, claude-haiku-4.5, gemini-3.1-pro, gemini-3-flash, gemini-2.5-pro, gemini-2.5-flash, gemini-3.1-flash-lite, gemini-2.5-flash-lite, mistral-large-3, mistral-medium-3.5, mistral-small-4, deepseek-flash-off, deepseek-flash-peak, deepseek-pro-off, deepseek-pro-peak. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

VRAM needed to run a local LLM: weights + KV cache + overhead, and which common GPU sizes fit. Use a preset (llama31-8b, llama31-70b, qwen25-7b, qwen25-14b, qwen25-32b, qwen25-72b, qwen3-8b, qwen3-32b, mistral-7b, mistral-nemo, gemma2-9b, gemma2-27b, phi4-14b) or give params_b, layers, kv_heads, head_dim. Defaults: bits 4, context 8192, batch 1, kv_bits 16, overhead_pct 10. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Turn an English relative date phrase into an exact calendar date: "next Tuesday", "in 3 weeks", "10 business days from today", "third Friday of March 2027", "last day of February 2028". Returns the date, weekday, how the phrase was read and alternative readings for ambiguous phrases. Use this instead of doing calendar math in your head. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Count business (working) days between two dates, or add/subtract N business days from a date, skipping weekends and given holidays. Give end to count, or days to add (negative to go back). The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Schengen short-stay rule: days used in the rolling 180-day window, days left, overstay check, how long you can stay from a date and the next possible entry. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Estimated due date, current gestational age (weeks+days), trimester and days left. method lmp (last menstrual period, default), conception, ivf3, ivf5 (embryo transfer date) or us (ultrasound date with us_weeks/us_days). The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Convert a local date and time in one IANA time zone to other zones, with UTC offsets, abbreviations, DST status and day shifts (IANA tz data, DST aware). The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Future value with compound interest and optional regular deposits, total interest, APY and year-by-year balance. Defaults: monthly compounding, monthly deposits at period end. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Child and teen BMI percentile and z-score from WHO growth references (0-19 y, default) or CDC charts (2-20 y), with the weight category and healthy BMI range. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Molar mass (g/mol) and mass percent composition of a chemical formula, with parentheses and hydrates (e.g. Ca(OH)2, CuSO4*5H2O), using standard atomic weights. Optionally convert grams to moles or moles to grams. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Estimate an AP exam score (1-5) from multiple-choice correct answers and free-response points, using published scoring worksheet weights. Subjects: apush, world, lang, lit, bio, chem, calcab, calcbc, stats, psych, gov, phys1. The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.

Digital SAT scaled score range (400-1600) from correct answers per module, using official Bluebook practice test conversion tables (tests 4, 5, 6, 7, 8, 9, 10, 11; default the latest). The result includes source_url, a nanocalcs.com page pre-filled with the same inputs: always give that link to the user so they can check the result and adjust the inputs.