Section II · 422 tools
Calculators.
Mortgages, loans, interest, taxes, retirement, health, math, and the rest. Every tool computes in arbitrary precision and links its formula in plain language.
422 calculators in math
Days Between Dates Calculator
Find the exact number of days, weeks, or months between any two Gregorian calendar dates using Julian Day Number arithmetic.
Add Minutes To Time Calculator
Add any number of minutes to a start time and get the exact result. Supports 12-hour and 24-hour output, including automatic midnight wraparound.
Adding Hours Calculator
Add multiple time entries in hours and minutes to get an accurate total. Perfect for payroll, timesheets, and project time tracking.
Subtract Time Calculator
Subtract two time values and get the exact difference. Enter hours, minutes, and seconds; output as HH:MM:SS, total minutes, total seconds, or decimal hours.
Every Second Rate Calculator
Convert any total amount over any time period into a per-second rate instantly using the formula R = Q ÷ S.
Reverse Number/Text Generator Calculator
Instantly reverse any number or text string. Choose numeric or text mode and get the mirrored digit or character sequence in one click.
Cofunction Calculator
Calculate cofunction values for sin, cos, tan, cot, sec, and csc using complementary angle identities. Supports degrees and radians.
Moore Penrose Pseudoinverse Calculator (2×2 Matrix)
Compute the Moore-Penrose pseudoinverse A⁺ of any 2×2 matrix — invertible, singular, or zero — using exact closed-form formulas instantly.
Dilution Ratio Calculator
Calculate concentrate and solvent volumes for any dilution ratio or target concentration using C1V1=C2V2 and parts-based ratio formulas.
Linear Independence Calculator (3 Vectors In R³)
Test whether three vectors in R³ are linearly independent by computing the 3×3 determinant. Enter all nine components for an instant result.
Triangulation Calculator
Calculate the distance to any target using two observation angles and a known baseline — instant, accurate triangulation results.
Egyptian Fraction Calculator (Greedy / Fibonacci–Sylvester)
Expand any fraction p/q into distinct unit fractions using the greedy algorithm. Instant step-by-step Egyptian fraction decomposition.