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
Class percentile rank of a score
% of classmates who scored lower
POST /edu/percentile-rank-class$0.002Developer Utilities
Weekly study hours per course
allocate by credits or difficulty
POST /edu/weekly-study-per-course$0.002Developer Utilities
APA format pages estimator
word count to APA paper pages
POST /edu/apa-pages-estimate$0.002Developer Utilities
Dissertation chapter word split
intro, methods, results, discussion
POST /edu/dissertation-chapters-split$0.002Developer Utilities
Pause-adjusted speech duration
word count, rate, and sentence pauses
POST /edu/pause-adjusted-speech$0.002Developer Utilities
Words needed for a speech
target minutes and speaking pace (WPM)
POST /edu/words-for-minutes$0.002Developer Utilities
Test score confidence band
true-score range from SEM
POST /edu/test-confidence-band$0.002Developer Utilities
Weighted final two-part grade
coursework + exam module mark
POST /edu/weighted-final-two-parts$0.002Developer Utilities
Language daily minutes for a goal
practice minutes per day
POST /edu/language-daily-minutes$0.002Developer Utilities
Long division with remainder
quotient, leftover, steps
POST /edu/long-division-steps$0.002Developer Utilities
CEFR level by study hours
estimate A1–C2 from guided hours
POST /edu/cefr-by-hours$0.002Developer Utilities
Greatest common factor calculator
GCF of two or more numbers
POST /edu/gcf-school$0.002Developer Utilities
Transverse shear stress calculator
τ = VQ/(It) beam formula
POST /eng/transverse-shear-stress$0.002Developer Utilities
Cantilever UDL moment calculator
fixed-end M = wL²/2
POST /eng/cantilever-udl-moment$0.002Developer Utilities
Parallel-axis theorem inertia calculator
I = Ī + A·d²
POST /eng/parallel-axis$0.002Developer Utilities
Corrected endurance limit calculator
Se = ka × kb × kc × Se'
POST /eng/endurance-limit$0.002Developer Utilities
Principal stress 2D calculator
Mohr's circle σ1, σ2, τmax
POST /eng/principal-stress-2d$0.002Developer Utilities
Brinell hardness number calculator
HBW from load, D and d
POST /eng/brinell-number$0.002Developer Utilities
Percent reduction of area calculator
RA% from A0 and Af
POST /eng/reduction-of-area$0.002Developer Utilities
Colebrook friction factor calculator
Darcy f from ε/D and Re
POST /eng/friction-colebrook$0.002Developer Utilities
Orifice discharge calculator
Q = Cd·A·√(2gh) from head
POST /eng/orifice-flow$0.002Developer Utilities
Cylindrical pipe conduction calculator
Q = 2πkLΔT / ln(ro/ri)
POST /eng/cylinder-conduction$0.002Developer Utilities
Gear output torque calculator
T_out = T_in × gear ratio
POST /eng/gear-output-torque$0.002Developer Utilities
Conductive heat flux calculator
q = k ΔT / L through a wall
POST /eng/heat-flux$0.002Developer Utilities
Overall heat transfer coefficient calculator
wall assembly U
POST /eng/overall-u$0.002Developer Utilities
Power screw efficiency calculator
η from lead angle and μ
POST /eng/power-screw-efficiency$0.002Developer Utilities
Helical spring rate calculator
k = G d⁴ / (8 D³ Na)
POST /eng/spring-rate-helical$0.002Developer Utilities
Area by double meridian distance
enclosed traverse area
POST /eng/area-dmd$0.002Developer Utilities
Horizontal curve long chord calculator
LC = 2R sin(Δ/2)
POST /eng/curve-long-chord$0.002Developer Utilities
Power factor correction kVAR calculator
Qc from P, PF
POST /eng/pf-correction$0.002Developer Utilities
Gantt task end date calculator
calendar or working days
POST /biz/gantt-task-end$0.002Developer Utilities
Work hours overlap percentage calculator
two-team UTC windows
POST /biz/work-hours-overlap-percent$0.002Developer Utilities
Motor efficiency calculator
η = P_out/P_in × 100%
POST /eng/motor-efficiency$0.002Developer Utilities
Effort variance calculator
planned vs actual hours
POST /biz/effort-variance$0.002Developer Utilities
No-meeting day time reclaimed calculator
hours a team gets back
POST /biz/no-meeting-day-savings$0.002Developer Utilities
Time to complete task list calculator
total and finish clock
POST /biz/tasklist-total-time$0.002Developer Utilities
Work-to-break ratio calculator
split a session into work and rest
POST /biz/work-break-ratio$0.002Developer Utilities
Booklet page imposition order
saddle-stitch print sequence
POST /date/booklet-page-order$0.002Developer Utilities
Oversize parcel surcharge calculator
overweight shipping fee
POST /ecom/oversize-surcharge$0.002Developer Utilities
Shipping cost by zone calculator
weight times zone rate
POST /ecom/shipping-cost-by-zone$0.002Developer Utilities
Cartons per pallet layer calculator
boxes on one pallet deck
POST /ecom/cartons-per-layer$0.002Developer Utilities
Postage stamps needed calculator
cover letter or parcel postage
POST /ecom/stamps-needed$0.002Developer Utilities
Household chore rotation calculator
assign chores fairly
POST /home/chore-rotation$0.002Developer Utilities
Gym cost per visit calculator
membership math
POST /life/gym-cost-per-visit$0.002Developer Utilities
Weeks lived so far calculator
full weeks from birth date
POST /date/weeks-lived$0.002Developer Utilities
Work anniversary date calculator
next date and days remaining
POST /date/work-anniversary$0.002Developer Utilities
Fraction of month elapsed calculator
% of the month, free
POST /date/fraction-of-month$0.002Developer Utilities
Round to nearest multiple
five, ten or quarter, free
POST /math/round-to-multiple$0.002Developer Utilities
Heart rate zones from reserve
percent HRR calculator, free
POST /health/hr-zones-percent-hrr$0.002Developer Utilities
Gellish max heart rate calculator
207 − 0.7 × age, free
POST /health/hrmax-gellish$0.002Developer Utilities
Weighted cost split calculator
each party's exact share free
POST /life/weighted-split$0.002Developer Utilities
Maffetone 180 aerobic heart rate
MAF HR from age, free
POST /health/maffetone-aerobic-hr$0.002Developer Utilities
Training impulse TRIMP calculator
Banister score from duration and HRR
POST /health/training-impulse-trimp$0.002Developer Utilities
Marathon time predictor calculator
Riegel from a shorter race
POST /health/marathon-time-predict$0.002Developer Utilities
Race pace band calculator
even km and mile clocks from a goal finish
POST /health/pace-band-splits$0.002Developer Utilities
Treadmill incline equivalent pace calculator
flat pace from speed & grade
POST /health/treadmill-incline-pace$0.002Developer Utilities
Sleep efficiency calculator
time asleep ÷ time in bed as %
POST /health/sleep-efficiency$0.002Developer Utilities
Net torque calculator
sum CW and CCW torques about a pivot
POST /mech/net-torque$0.002Developer Utilities
Gravity neutral point calculator
null field between two masses
POST /mech/gravity-null-point$0.002Developer Utilities
Pendulum frequency calculator
simple period and f
POST /mech/pendulum-frequency$0.002