Developer Utilities
Small developer utilities that save a trip to a random website. Encode and decode Base64, explain a regex, build UTM links, generate QR codes and vCards, and more — the everyday helpers. Free in your browser, and available by API when you need them in a script.
Developer Utilities
Marginal Cost vs Average Cost: Is ATC Rising or Falling?
POST /econ/marginal-cost-average-cost-relation$0.002Developer Utilities
Marginal external cost calculator
MEC = MSC − MPC, free
POST /econ/marginal-external-cost$0.002Developer Utilities
Marginal rate of substitution calculator
MRS = MU_x / MU_y
POST /econ/marginal-rate-of-substitution$0.002Developer Utilities
Marginal Revenue from Total Revenue Calculator
POST /econ/marginal-revenue-from-total$0.002Developer Utilities
Marginal Social Benefit Calculator
POST /econ/marginal-social-benefit$0.002Developer Utilities
Marginal Utility from Total Utility Calculator
POST /econ/marginal-utility-from-total$0.002Developer Utilities
Optimal markup from demand elasticity
inverse-elasticity rule
POST /econ/markup-from-elasticity$0.002Developer Utilities
Mixed strategy Nash equilibrium 2×2 calculator
indifference probs
POST /econ/mixed-strategy-2x2$0.002Developer Utilities
Monopoly Deadweight Loss Calculator for a Linear Market
POST /econ/monopoly-deadweight-loss$0.002Developer Utilities
MPC from MPS calculator
MPC = 1 − MPS, free
POST /econ/mpc-from-mps$0.002Developer Utilities
National income from GDP calculator
NDP, NNP, NI free
POST /econ/national-income-from-gdp$0.002Developer Utilities
Nominal to Real Wage CPI Calculator
POST /econ/nominal-to-real-wage$0.002Developer Utilities
Okun's law output gap calculator
estimate GDP gap
POST /econ/okun-law-output-gap$0.002Developer Utilities
Opportunity cost ratio calculator
PPF slope between two goods
POST /econ/opportunity-cost-ratio$0.002Developer Utilities
Optimal Consumption Calculator
Compare MRS with the Price Ratio
POST /econ/optimal-consumption-mrs-price-ratio$0.002Developer Utilities
Output Gap Calculator
Actual vs Potential GDP
POST /econ/output-gap$0.002Developer Utilities
Payoff Matrix Expected Value Calculator for Mixed Strategies
POST /econ/payoff-matrix-expected-value$0.002Developer Utilities
Third-Degree Price Discrimination Calculator
POST /econ/price-discrimination-two-markets$0.002Developer Utilities
Price elasticity of demand midpoint calculator
arc PED, free
POST /econ/price-elasticity-demand-midpoint$0.002Developer Utilities
Price Floor Surplus Calculator
Excess Supply from Linear Curves
POST /econ/price-floor-surplus$0.002Developer Utilities
Quantity supplied from a linear supply function calculator
POST /econ/quantity-supplied-linear$0.002Developer Utilities
Quantity theory of money calculator
solve MV=PQ for M, V, P or Q
POST /econ/quantity-theory-money$0.002Developer Utilities
Quintile Income Share Ratio Calculator (S80/S20)
POST /econ/quintile-share-ratio$0.002Developer Utilities
Real exchange rate calculator
e × (P* / P) relative purchasing power
POST /econ/real-exchange-rate$0.002Developer Utilities
Required Reserves Calculator
Find Excess Reserves
POST /econ/required-reserves$0.002Developer Utilities
Second-price auction calculator
Vickrey winner and price paid
POST /econ/second-price-auction$0.002Developer Utilities
Two-Player Shapley Value Calculator
Fair Surplus Allocation
POST /econ/shapley-value-two-player$0.002Developer Utilities
Subsidy incidence calculator
buyer and seller share
POST /econ/subsidy-incidence-share$0.002Developer Utilities
Per-Unit Subsidy Market Effect Calculator
POST /econ/subsidy-market-effect$0.002Developer Utilities
Supply schedule table from linear supply function
Qs by price
POST /econ/supply-schedule-from-function$0.002Developer Utilities
Supply Shift New Equilibrium Calculator
POST /econ/supply-shift-new-equilibrium$0.002Developer Utilities
Tariff Consumer Surplus Loss Calculator
POST /econ/tariff-consumer-loss$0.002Developer Utilities
Tariff Revenue Calculator
Imports Remaining After a Tariff
POST /econ/tariff-revenue$0.002Developer Utilities
Theil index calculator
inequality T from income distribution
POST /econ/theil-index-distribution$0.002Developer Utilities
Total market surplus calculator
consumer + producer at equilibrium
POST /econ/total-surplus-market$0.002Developer Utilities
Consumption beyond PPF from trade
specialization & terms of trade
POST /econ/trade-gain-consumption$0.002Developer Utilities
Value of Marginal Product of Labor Calculator
POST /econ/value-of-marginal-product$0.002Developer Utilities
Zero-Sum Game Value Calculator
2x2 Optimal Strategies
POST /econ/zero-sum-game-value$0.002Developer Utilities
Average of grades calculator
mean, total, and count
POST /edu/average-of-grades$0.002Developer Utilities
CEFR vocabulary target
how many words to learn to the next level
POST /edu/cefr-vocab-target$0.002Developer Utilities
Citation Density Calculator
Citations per 1,000 Words
POST /edu/citation-density$0.002Developer Utilities
Class exam average calculator
mean, highest, lowest, and range of scores
POST /edu/class-exam-average$0.002Developer Utilities
Cosine Text Similarity Calculator
Compare Word Frequency Vectors
POST /edu/cosine-text-similarity$0.002Developer Utilities
Course load weekly hours
contact + study across enrolled courses
POST /edu/course-load-hours$0.002Developer Utilities
Current Grade Percentage Calculator
Graded Work Only
POST /edu/current-grade-percentage$0.002Developer Utilities
Daily study hours for goal
hours per day until your deadline
POST /edu/daily-study-goal$0.002Developer Utilities
Debate speaking time split
constructive, rebuttal & CX by format
POST /edu/debate-time-split$0.002Developer Utilities
Direct Proportion Solver
Find the Missing Ratio Term
POST /edu/direct-proportion$0.002Developer Utilities
Effective reading rate with comprehension
WPM × accuracy
POST /edu/effective-reading-rate$0.002Developer Utilities
Essay Completion Percentage Calculator
Track Words Left
POST /edu/essay-completion-percent$0.002Developer Utilities
Exam Pass Threshold Checker
Score, Percentage and Margin
POST /edu/exam-pass-threshold$0.002Developer Utilities
Exam Prep Timeline Builder
Schedule Every Topic Before Test Day
POST /edu/exam-prep-timeline$0.002Developer Utilities
Exam topics coverage
% of syllabus topics you have studied
POST /edu/exam-topics-coverage$0.002Developer Utilities
Exponent power calculator
base^n with zero and negative exponents
POST /edu/exponent-power$0.002Developer Utilities
Daily flashcard review load calculator
POST /edu/flashcard-review-load$0.002Developer Utilities
Flat Bump Grade Curve Calculator
POST /edu/flat-bump-curve$0.002Developer Utilities
Simplify fraction to lowest terms
reduce by GCD free
POST /edu/fraction-simplify$0.002Developer Utilities
GPA 10 to 4 point converter
Indian CGPA to US GPA (×0.4)
POST /edu/gpa-10-to-4-scale$0.002Developer Utilities
GPA after dropping a course
recompute average without withdrawn class
POST /edu/gpa-after-dropping-course$0.002Developer Utilities
GPA from letter grades calculator
credit-weighted GPA
POST /edu/gpa-from-letter-grades$0.002