TinyJSTools
Free online calculators and interactive tools
From prime numbers and geometry to maps and visualizations — fast, accurate and mobile-friendly.
TinyJSTools is a collection of free online calculators, math tools, geography tools and interactive visualizations. Every tool runs directly in your browser with no registration required, and many include step-by-step explanations to help you understand how the result is obtained.
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Latest Tools
Chess Elo Percentile
Enter your FIDE Elo and see your percentile worldwide. Compare classical, rapid, and blitz ratings against the June 2026 FIDE distribution (553,711 classical · 454,968 rapid · 302,938 blitz players).
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FIDE Chess Players Globe
Explore 749,459 FIDE-rated chess players on an interactive 3D globe. Choropleth map by country with male/female breakdown, top-10 rankings, and per-million density. Data: June 2026.
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Binomial Coefficient Calculator
Compute C(n, k) = n! / (k!(n−k)!) instantly. Step-by-step factorial computation, Pascal's triangle with the selected cell highlighted, and a full educational explanation.
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Binomial Distribution Calculator
Calculate P(X=k), P(X≤k), P(X>k), mean, variance, and standard deviation for B(n, p). Interactive bar chart and full educational explanation.
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Percentage Calculator
Five calculators in one: X% of Y, what percent, percentage change, reverse percentage, and add or remove a percentage. Real-time results with formulas.
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Fraction Calculator
Add, subtract, multiply and divide fractions with step-by-step explanations and automatic reduction. Virtual keyboard with frac(a;b) notation.
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All Tools by Category
Converters
Convert between number systems and formats — Roman numerals and more.
1 tool
Games
Interactive tools for games: animated dice simulator with live probability stats, chess Elo percentile calculator with FIDE distribution chart, and a 3D globe of FIDE-rated players.
3 tools
Geography
Explore cities, latitudes, world maps, population density, forest coverage and population radius with data from 70,000+ populated places.
7 tools
Geometry
Precise tools for calculating lengths, areas, and volumes of geometric shapes.
5 tools
Mathematics
Fraction calculator, GCD/LCM, divisors, quadratic solver, binomial coefficient and distribution, prime checker, pi digits, base converter — with step-by-step explanations.
15 tools
Random
Cryptographically random tools: number generator, list picker, password generator, coin flip, and color generator.
5 tools
Statistics
Statistics calculator plus guides on mean, median, mode, standard deviation, and when to use each.
6 tools