Collaborative Calculator Tools

How much house you can afford based on income and debts

When refinancing pays off given new terms and closing costs

Compare adjustable-rate vs fixed-rate mortgages

Compare renting vs buying based on costs and appreciation

Car payment calculator with down payment and trade-in

Unsecured loan payment calculator with fees

Education debt planning across repayment plans

Impact of extra payments on payoff timeline

Debt payoff optimizer using smallest-balance-first method

Interest-optimized debt payoff strategy

Home equity line of credit calculator

Time and contributions needed to reach a savings target

Retirement account growth with employer match

IRA comparison based on current vs retirement tax rates

RMD calculator based on account balance and age

Benefit estimator based on earnings and claiming age

Withdrawal planning with inflation adjustment

Financial independence and early retirement planning

DCA vs lump sum investment comparison

Total return including dividends over a holding period

DRIP calculator with dividend growth rate

Yield to maturity and current yield calculator

How much to save based on expenses and risk tolerance

Federal income tax calculator by filing status

Find your marginal tax rate and bracket

Take-home pay after taxes and deductions

SE tax on net self-employment income

Tax on investment gains by holding period

W-4 optimizer for accurate withholding

Quarterly estimated tax payment calculator

Health savings account tax benefit calculator

Education savings plan tax calculator

Real estate tax estimator with exemptions

Unit and revenue break-even point calculator

Gross and net margin from revenue and costs

Price calculation from cost and markup percentage

Operating cash flow analysis

Net present value of future cash flows

Internal rate of return for investment decisions

Return on investment from gain and cost

Time to recoup an initial investment

Simple valuation using revenue and earnings multiples

Net 30/60/90 with early payment discount

Cubic yards or meters needed for a pour

Number of bags needed for a given volume

Reinforcement layout for slabs and walls

Simple beam calculator for span and load

Floor joist layout by span and lumber size

Rise, run, and headroom for stairway design

ADA compliance checker for ramp grade

Foundation sizing by load and soil capacity

Block and material estimator for retaining walls

Deck and fence post layout calculator

Board feet calculator for dimensional lumber

Sheets needed for room dimensions and openings

Gallons needed by wall area and number of coats

Square footage with waste factor for flooring

Tiles and grout needed for a given area

Shingles and materials by roof dimensions and pitch

Material estimation for exterior siding

Batts or blown-in insulation by area and R-value

Masonry units needed for wall dimensions

Cubic yards needed by area and depth

Posts, rails, and pickets for fence construction

Ampacity calculator for conductor sizing

Voltage drop over wire distance and gauge

Panel load calculator for all circuits

Maximum wires allowed in a conduit size

Breaker sizing by load and wire size

Flow rate calculator by fixture units

Size needed based on household and usage

Proper drainage pitch by pipe diameter

Pressure loss from elevation, pipe length, and fittings

Heating and cooling load by square footage

CFM and duct dimensions for room airflow

Simplified Manual J load calculation

Heating capacity for home size and climate

Cooling capacity needed by area and exposure

Multiply or divide recipe ingredient amounts

Per-person amounts from total quantity

Commercial batch sizing for large-scale recipes

Flour-based ratios for bread recipes

Convert between fresh, active dry, and instant yeast

Volume equivalents across pan shapes and sizes

Replacement calculator for common egg substitutes

Volume to weight conversion by flour type

Dough hydration percentage from flour and water weight

Starter feeding ratios and timing

Volume and weight conversion for cooking

Fahrenheit, Celsius, and gas mark conversion

Adjust cooking time for different portion sizes

Time and temperature by cut, weight, and doneness

High altitude baking adjustments

Scale cocktail recipes for batch preparation

Alcohol by volume from ingredient volumes and ABVs

Ice and water dilution for spirits

Sugar-to-water ratios for 1:1 and rich syrups

Brew ratio by coffee weight, water, and method

Steep time and temperature by tea type

Total calories from meal ingredients and amounts

Protein, carb, and fat breakdown by food

Per-serving nutrition facts for a full recipe

Daily caffeine intake tracker from beverages

Food quantities for events by guest count and duration

Commercial quantities by headcount and menu

Meat per person by guest count and meat types

Number of pizzas needed by guest count

Basal metabolic rate by age, sex, height, and weight

Total daily energy expenditure with activity level

Body fat percentage using multiple methods

Ideal weight range by height, sex, and frame size

WHR calculator from waist and hip circumference

LBM calculator from weight and body fat percentage

1RM estimator from weight lifted and reps

Running pace, time, or distance from any two

Training zones from age and resting heart rate

Calorie burn by activity, duration, and weight

Convert step count to distance by stride length

Pool and open water pace calculator

Watts estimator from speed, weight, and grade

Weight loss calculator from current weight and goal

Macro ratio calculator by calories and diet type

Daily protein requirement by weight and activity

Hydration calculator by weight, activity, and climate

Eating window calculator from start time and fasting hours

Pregnancy due date from last menstrual period

Fertility window from cycle length and last period

Weight-based dosing reference calculator

BAC estimator from drinks, weight, sex, and time

eGFR calculator from creatinine, age, and sex

Fraction arithmetic and simplification

Ratio calculator and solver

Solve proportions given three of four values

Mean, median, and mode of a number set

Spread and variance of a data set

Find prime factors of an integer

Greatest common divisor and least common multiple

Logarithm calculator for any base

Power calculator for base and exponent

Convert numbers to and from scientific notation

Area, perimeter, and angles of a triangle

Area and circumference from radius or diameter

Area, perimeter, and diagonal of a rectangle

Regular polygon area and properties

Volume and surface area of a sphere

Volume and surface area of a cylinder

Volume and surface area of a cone

Volume and surface area of a pyramid

Right triangle solver using the Pythagorean theorem

Solve ax² + bx + c = 0 for x

Solve linear equations for x

Solve 2x2 and 3x3 systems of equations

Find zeros of a polynomial

Factor algebraic expressions

Z-scores and probabilities for normal distribution

Binomial probability calculator

Poisson probability distribution

Chi-square goodness of fit test

Statistical significance using t-test

CI calculator from sample mean, SD, and size

Required sample size for margin of error

nPr permutation calculator

nCr combination calculator

Weighted average from values and probabilities

Posterior probability from prior and likelihood

Speed, distance, and time calculator

Kinematic calculator from known values

F = ma force calculator

p = mv momentum calculator

KE calculator from mass and velocity

PE calculator from mass and height

Trajectory calculator from velocity and angle

Friction force from normal force and coefficient

V = IR voltage, current, and resistance

Electrical power from voltage and current

Wave properties from frequency and speed

Sound intensity and power ratio calculator

Molecular weight from chemical formula

Solution concentration from solute and volume

C1V1 = C2V2 dilution calculator

pH, pOH, and hydrogen ion concentration

PV = nRT with any variable as unknown

Reaction calculator from balanced equation

Element percentages in a compound

Determine formula from mass data

Days, weeks, and months between two dates

Find a future or past date from a start date

Exact age in years, months, and days

Day of the week for any date

Business days between dates excluding holidays

Convert time across multiple time zones

Convert between Unix epoch and human-readable dates

Days remaining until a target date

Hours and minutes between two times

Check whether a year is a leap year

ISO week number for any date

Julian day number converter

MPG and liters per 100km calculator

Trip fuel expense from distance and efficiency

Electric vehicle range from battery and efficiency

Charge time from battery size and charger power

Compare tire sizes and their effects

Speed difference from tire size changes

CC, CI, and liter conversion from bore and stroke

HP and torque converter from RPM

Theoretical acceleration from HP and weight

Final drive calculator from tire size and gearing

Vehicle value over time by age and mileage

Total cost comparison for leasing vs buying

Payload calculator from GVWR and curb weight

Square footage for lawn dimensions and shapes

Application rate by lawn size and product

Grass seed needed by area and seed rate

Cubic yards of mulch by area and depth

Compost and amendment quantity for garden beds

Number of plants needed for area and spacing

Watering schedule by zone, plant type, and climate

Fill volume for raised bed dimensions

Square footage from length and width

Rolls needed for room dimensions and pattern repeat

Window treatment sizing by window dimensions

Yards or meters needed for room dimensions

Lumens needed by room size and use

Fan diameter for room square footage

BTU needed for a single room

Power bill estimator from watts, hours, and rate

Water bill estimator from usage and rate

PV system savings by roof size and location

Days of fuel from tank size and daily usage

Required watts for appliances to power

Flight duration from origin and destination distance

Exchange rate calculator between currencies

Bag weight allocator for packing limits

Trip cost estimator by destination and duration

Road trip fuel cost from distance and MPG

Trip duration from distance and average speed

Points vs cash value comparison

Flight miles value by redemption option

Group expense divider for shared costs

Recovery time estimator from time zones crossed

Day length and sun times by location and date

Annual salary and hourly rate converter

Rate calculator from desired income and expenses

Meeting expense from attendees, salaries, and duration

Email campaign calculator from open and conversion rates

CLV from average purchase, frequency, and lifespan

Customer loss rate over a time period

Runway calculator from monthly spend and cash

MRR, ARR, and other SaaS revenue metrics

Statistical significance for A/B test variants

Conversion rate from visitors and conversions

Ad cost calculator from clicks, impressions, and spend

Return on ad spend from revenue and ad cost

Grade point average from grades and credit hours

Final exam score needed for desired course grade

Grade with category weighting

Percentage score from correct and total questions

Time to read from word count and reading speed

Time allocation across subjects

Award value calculator by tuition and terms

Monthly payment by loan amount, rate, and term

4-year cost projector with inflation

Dice roller with statistics for tabletop RPGs

Game odds from favorable and total outcomes

Deck probability for desired draws

Turn timer by number of players

Scale converter for model building

Yarn calculator from gauge and dimensions

Thread and fabric calculator for pattern size

Exposure calculator for ISO, aperture, and shutter

Tempo calculator from beats and time

Handmade item pricing from materials and time

Sport-specific stat calculators

CO2 calculator from activities and consumption

Grid emissions by kWh and location

Travel carbon footprint by route and class

Vehicle CO2 by distance and vehicle type

Water usage calculator by activity

Environmental savings from materials recycled

Solar system payback from cost and production

Carbon offset by tree type and quantity

Efficiency calculator from home details and usage

Daily food amount by weight, age, and activity

Feeding calculator by weight, age, and food type

Human years converter by pet age and species

Tank volume from dimensions

Fish per gallon by tank size and species

Dosage calculator by pet weight and medication

Annual expense estimate by pet type and care level

Mechanical advantage from teeth counts

Torque from force and lever arm distance

Mechanical advantage from pulley configuration

Hooke's law from force and displacement

Length change from material and temperature

Q = mcDT heat energy calculator

Pressure from force and area

Volume flow from pipe diameter and velocity

Flow regime from velocity, diameter, and viscosity

Distributed load analysis for beams

Cross-section properties for structural shapes

Material properties from force, area, and modulus