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
Rideshare fare estimate
base, mile & minute from distance/time
POST /travel/rideshare-fare-estimate$0.002Developer Utilities
Baking pan size converter
adjust recipe quantities and time
POST /cook/baking-pan-size-convert$0.002Developer Utilities
Egg size substitution calculator
convert eggs by volume
POST /cook/egg-size-substitute$0.002Developer Utilities
Brine Salt and Water Ratio Calculator
POST /cook/brine-ratio-calculate$0.002Developer Utilities
Coffee-to-water brew ratio calculator
POST /cook/coffee-ratio-calculate$0.002Developer Utilities
Restaurant food cost percentage calculator
price menu items for a target
POST /cook/food-cost-percentage$0.002Developer Utilities
Slow cooker time converter
recipe cook time to LOW/HIGH hours
POST /cook/slow-cooker-time-convert$0.002Developer Utilities
Sourdough dough hydration
baker's % from flour, water & starter
POST /cook/sourdough-hydration-calc$0.002Developer Utilities
Wine bottle calculator for a party
servings and guests
POST /cook/wine-serving-count$0.002Developer Utilities
Recipe batch total cost calculator
ingredients × unit cost ÷ servings
POST /cook/batch-recipe-cost$0.002Developer Utilities
Recipe calorie calculator
total and calories per serving
POST /cook/calorie-count-recipe$0.002Developer Utilities
Cooking oil smoke point lookup
temperatures and suitable uses
POST /cook/smoke-point-lookup$0.002Developer Utilities
Humidex calculator
Canadian humidex from temperature and dew point
POST /weather/humidex-calculate$0.002Developer Utilities
Wind chill calculator
calculate feels-like temperature
POST /weather/wind-chill-calculate$0.002Developer Utilities
Classify an Air Quality Index Category and Health Guidance
POST /weather/air-quality-index-category$0.002Developer Utilities
Convert barometric pressure units
hPa/mb, inHg and mmHg
POST /weather/barometric-pressure-convert$0.002Developer Utilities
Simplified reference evapotranspiration estimate for irrigation
POST /weather/evapotranspiration-estimate$0.002Developer Utilities
Frost and freeze risk check
classify overnight low for gardens
POST /weather/frost-freeze-risk-check$0.002Developer Utilities
Hurricane category by wind speed
Saffir-Simpson scale lookup
POST /weather/storm-surge-category-lookup$0.002Developer Utilities
Beaufort wind scale lookup
force number and conditions
POST /weather/wind-speed-scale-lookup$0.002Developer Utilities
Pollen Count Severity Category Classifier
POST /weather/pollen-count-category$0.002Developer Utilities
Snow-to-liquid ratio estimator
predict snow accumulation from temperature
POST /weather/snow-to-liquid-ratio-estimate$0.002Developer Utilities
Explain Unix file permission octal
owner, group, and others
POST /security/file-permission-octal-explain$0.002Developer Utilities
Compare cost per serving for two recipes
POST /math/recipe-cost-per-serving-compare$0.002Developer Utilities
Split a tip pool by hours worked
proportional calculator
POST /math/tip-pool-split-by-hours$0.002Developer Utilities
Compare unit price between products
find the better value
POST /math/unit-price-compare$0.002Developer Utilities
Group expense settle-up
minimum payments to clear debts free
POST /math/who-owes-who-settle-up$0.002Developer Utilities
Check Cookie Security Attributes
Secure, HttpOnly and SameSite
POST /security/cookie-attribute-check$0.002Developer Utilities
Check flight layover connection time
comfortable, tight, or risky
POST /travel/layover-time-check$0.002Developer Utilities
Airline luggage weight limit checker and overweight fee tier
POST /travel/luggage-weight-check$0.002Developer Utilities
SPDX license identifier lookup
names and summaries
POST /dev/license-spdx-lookup$0.002Developer Utilities
Generate README badge Markdown with alt text
POST /dev/readme-badge-markdown$0.002Developer Utilities
Visa requirement check
passport vs destination lookup stub
POST /travel/visa-required-check-stub$0.002Developer Utilities
API rate limit calculator
windows and batch delay budget
POST /dev/api-rate-limit-calc$0.002Developer Utilities
Pagination offset and limit calculator
total pages
POST /dev/pagination-offset-calc$0.002Developer Utilities
Resolve a slug collision with an incrementing numeric suffix
POST /dev/slug-collision-resolve$0.002Developer Utilities
Generate a complementary color from any hex or RGB value
POST /color/complementary-generate$0.002Developer Utilities
Validate an environment variable name
POSIX naming check
POST /dev/env-var-name-validate$0.002Developer Utilities
Rubric weighted score calculator
aggregate criteria and grades
POST /edu/rubric-score-aggregate$0.002Developer Utilities
Student-teacher ratio calculator
check a class-size target
POST /edu/class-size-ratio-check$0.002Developer Utilities
Book reading level matcher
find suitable books for a student
POST /edu/reading-level-book-match$0.002Developer Utilities
Split a class into evenly sized study groups
POST /edu/study-group-size-split$0.002Developer Utilities
Mortgage affordability calculator
estimate payment and loan amount
POST /realestate/mortgage-affordability$0.002Developer Utilities
Simplify mixed fraction
convert improper and mixed free
POST /math/mixed-fraction-simplify$0.002Developer Utilities
Down payment calculator
calculate cash and loan amount
POST /realestate/down-payment-calc$0.002Developer Utilities
Lease rent escalation calculator
yearly rent schedule
POST /realestate/lease-escalation-calc$0.002Developer Utilities
Check password patterns
keyboard walks, repeats, and substitutions
POST /security/password-breach-pattern-check$0.002Developer Utilities
Add or subtract days from a date
calendar date calculator
POST /math/add-subtract-days$0.002Developer Utilities
Calculate countdown to a target date in days, hours and minutes
POST /math/countdown-to-date$0.002Developer Utilities
Calculate basal metabolic rate with the Mifflin-St Jeor equation
POST /math/bmr-calculate$0.002Developer Utilities
Calculate paint needed for an area
coats and coverage calculator
POST /math/paint-area-coverage$0.002Developer Utilities
Estimate pregnancy due date
LMP + 280 days (Naegele)
POST /math/pregnancy-due-date$0.002Developer Utilities
Predict race finish time with Riegel's formula
POST /math/race-finish-time-predict$0.002Developer Utilities
Calculate time difference between UTC offsets
POST /math/time-zone-offset-diff$0.002Developer Utilities
Calculate tiles needed for a floor area with waste allowance
POST /math/tile-flooring-count$0.002Developer Utilities
Find overlapping meeting hours across time zones
free
POST /travel/time-zone-meeting-finder$0.002Developer Utilities
Test score curve calculator
adjust grades with three methods
POST /edu/test-curve-adjust$0.002Developer Utilities
Calculate class attendance percentage and check a policy threshold
POST /edu/attendance-percentage$0.002Developer Utilities
Allocate Exam Time per Question by Points
POST /edu/exam-time-per-question$0.002Developer Utilities
Merge flashcard decks
dedupe by front, keep first card
POST /edu/flashcard-deck-merge$0.002