Generators, calculators, and productivity helpers for agents and everyday tasks. Every page offers a guide—not only a form.
Compute exact years, months, and days between a birth date and a reference date using calendar arithmetic.
Convert between bytes, KB, MB, GB, and TB using binary (1024-based) factors in your browser.
Find the whole-day difference between a start date and end date using UTC midnight boundaries.
Enter a value in feet and instantly convert it to meters in your browser.
Apply Gregorian leap-year rules to any year from 1 to 9999 and see yes or no instantly.
Calculate modulo Processing runs locally in your browser.
Use our tool to calculate your estimated mortgage payments
Compute the percentage increase or decrease between two values quickly.
Convert temperatures between Celsius, Fahrenheit, and Kelvin with instant results.
Switch between length, weight, and volume units and convert values with one tool.
Find what percentage the first number represents of the second one.
Calculate the value when you take a given percentage of a number.
Count k-length sequences from n symbols when each position may repeat any symbol (n^k cases)
Count k-length ordered selections from n distinct items without reuse—the nPk partial permutation
Reduce width and height to a ratio and optionally scale to a target edge
Split long documents into overlapping chunks sized for RAG ingestion or map-reduce agent workflows.
Count multisets of size k from n types when the same element may appear more than once
Count unordered k-subsets from n distinct items without replacement—the binomial n choose k
Project savings growth with compound interest and compounding frequency
Estimate token usage and see whether pasted text fits common model context windows before sending prompts.
Select a time and start a countdown by clicking the start button, easily and online
Find elapsed days, weeks, months, and years between two calendar dates with optional direction.
Compute sale price and savings from an original price and percent off
Rough token budget from UTF-8 byte length using a chars-per-token heuristic before calling language models.
Convert Arabic numerals (1–3999) into standard Roman numeral notation.
Parse Roman numerals and convert them back to Arabic integers.
Multiply input and output token counts by per-million pricing to forecast API spend without calling a provider.
Count permutations of multiset objects when symbols repeat within fixed-length patterns
Count ordered arrangements of n distinct items taken all at once—the factorial n! formula
Convert the time using different time zones
Enter distance and average speed to calculate the estimated travel time for your trip.