Math & Numbers

Design a normal-weight concrete mix per ACI 211.1-91 absolute-volume method. Inputs: slump, nominal max aggregate size, air entrainment, water-cement ratio w/c, fineness modulus of sand, and dry-rodded coarse-aggregate density. Outputs the per-cubic-meter masses of cement, water, fine and coarse aggregate plus the mass ratio.

Math & Numbers

Calculate the basic rating life of a rolling bearing: L10 = (C/P)^p, with p = 3 for ball bearings and p = 10/3 for roller bearings. When a speed is provided, converts to L10h in operating hours.

Math & Numbers

Calculate the follower displacement, velocity coefficient, acceleration coefficient and pressure angle during the cam rise phase. Supports constant-velocity, constant-acceleration, harmonic (SHM) and cycloidal motion laws.

Math & Numbers

Calculate the ratio, driven speed and belt linear speed of a belt drive. i = d₂/d₁ = n₁/n₂, belt speed v = π·d·n/60. Supports mm/cm/m/inch diameter units.

Math & Numbers

Convert between bolt tightening torque and axial clamp force. T = K·F·d, where K is the nut factor (~0.20 for dry steel). Solve torque from force, or force from torque.

Math & Numbers

Calculate the ratio, driven speed and chain linear speed of a chain drive. i = z₂/z₁ = n₁/n₂, chain speed v = z₁·p·n₁/60000. Enter the pitch to compute chain speed.

Finance

Calculate the true Annual Percentage Rate (APR) of a loan when upfront fees are involved. The nominal interest rate sets the monthly payment, but fees reduce the net cash received, raising the effective APR. Uses Newton's method to solve the annuity present-value equation. Shows APR, nominal rate, monthly payment, and the APR premium.

Finance

Calculate your car loan monthly payment factoring in vehicle price, down payment, trade-in value, sales tax, and registration fees. Shows amount financed, total interest, total cost, a descending balance curve, and a yearly amortization schedule.

Finance

Calculate credit card cash back rewards across multiple spending categories. Enter categories as 'name, monthly spend $, cash back %' per line. Shows monthly and annual cash back per category, total rewards, effective cash-back rate, and a comparison against a flat-rate card.

Finance

Compare avalanche (highest APR first) vs snowball (lowest balance first) strategies for paying off multiple credit cards. Enter cards as 'name, balance, APR%, minPayment%' per line plus an extra monthly payment. Shows payoff time, total interest, savings vs minimum-only, and balance decline curves.

Finance

Calculate the compound annual growth rate (CAGR) from a beginning value, ending value and number of years; compare with the simple average growth rate and visualize the smooth growth curve. CAGR = (EV/BV)^(1/n) - 1.

Math & Numbers

Convert numbers and text between any radix from 2 to 36, with custom alphabets and presets for Base58, Base62, and Crockford Base32.