Glossary
Plain definitions of the terms the calculators use, from APR and amortization to BMR, R-value and z-score, each linked to its calculator.
A
- Amortization
- Paying off a loan through regular payments that each cover the interest due and repay part of the principal.
- Calculator: Mortgage Amortization
- Annual percentage rate (APR)
- The yearly cost of borrowing expressed as a percentage, without compounding within the year.
- Calculator: Loan
- Annual percentage yield (APY)
- The yearly return on a deposit once interest compounding within the year is included.
- Calculator: Certificate Of Deposit
- Annuity
- A series of equal payments made at regular intervals for a set period.
- Calculator: Annuity Income From Lump Sum
B
- Basal metabolic rate (BMR)
- The energy your body uses at complete rest to keep its vital functions running.
- Calculator: BMR
- Board foot
- A unit of lumber volume equal to a board 12 inches long, 12 inches wide and 1 inch thick.
- Calculator: Board Feet
- Body mass index (BMI)
- Weight in kilograms divided by the square of height in metres, a population-level screen of weight for height.
- Calculator: BMI
- Body surface area (BSA)
- The estimated total area of the skin, computed from height and weight and used to scale some medical doses.
- Calculator: Body Surface Area
- Bond yield
- The return a bond pays relative to its price, combining its coupons and the gain or loss at maturity.
- Calculator: Bond Yield
- Break-even point
- The sales volume at which revenue exactly covers fixed and variable costs.
- Calculator: Break Even Point
- British thermal unit (BTU)
- The heat needed to raise one pound of water by one degree Fahrenheit, about 1,055 joules.
- Calculator: Btu To Kilowatts
C
- Calorie
- A unit of energy equal to 4.184 joules; food labels count in kilocalories.
- Calculator: Energy Joules To Calories
- Capitalization rate
- A property's net operating income divided by its value, used to compare rental investments.
- Calculator: Cap Rate
- Compound annual growth rate (CAGR)
- The constant yearly rate that would take a value from its starting level to its ending level over a period.
- Calculator: Cagr Calculator
- Compound interest
- Interest calculated on the principal plus the interest already earned, so growth accelerates over time.
- Calculator: Compound Interest
- Credit utilization ratio
- The share of your available revolving credit that you are currently using.
- Calculator: Credit Utilization Ratio
D
- Debt avalanche
- A payoff method that puts every extra payment on the debt with the highest interest rate first.
- Calculator: Debt Payoff
- Debt service coverage ratio
- Net operating income divided by the debt payments due over the same period.
- Calculator: Debt Service Coverage Ratio
- Debt-to-income ratio
- Monthly debt payments divided by gross monthly income, used by lenders to judge what you can borrow.
- Calculator: Debt To Income Ratio
- Dew point
- The temperature at which air becomes saturated and water vapour starts to condense.
- Calculator: Dew Point
- Discriminant
- The value b² − 4ac of a quadratic equation, whose sign tells whether it has two, one or no real roots.
- Calculator: Quadratic Discriminant
- Dollar-cost averaging
- Investing a fixed amount at regular intervals regardless of price, so more units are bought when prices are low.
- Calculator: Dollar Cost Averaging
E
- Emergency fund
- Cash set aside to cover several months of essential expenses after a job loss or an unexpected cost.
- Calculator: Emergency Fund
- Escape velocity
- The minimum speed an object needs to leave a body's gravity without further propulsion.
- Calculator: Escape Velocity
- Estimated due date
- The expected birth date, conventionally 280 days after the first day of the last menstrual period.
- Calculator: Pregnancy Due Date
F
- Fahrenheit
- A temperature scale on which water freezes at 32 °F and boils at 212 °F.
- Calculator: Temperature Celsius To Fahrenheit
- Future value
- What a sum invested today will be worth at a later date at a given rate of return.
- Calculator: Future Value Lump Sum
G
- Golden ratio
- The proportion of about 1.618 in which the whole is to the larger part as the larger part is to the smaller.
- Calculator: Golden Ratio Dimension
- Greatest common divisor (GCD)
- The largest whole number that divides two numbers without a remainder.
- Calculator: Gcd Two Numbers
- Gross margin
- Revenue minus the cost of goods sold, expressed as a share of revenue.
- Calculator: Gross Margin
H
- Heart rate reserve
- Maximum heart rate minus resting heart rate, the basis of the Karvonen training method.
- Calculator: Heart Rate Reserve
- Heart rate zones
- Training intensity bands defined as percentages of maximum heart rate.
- Calculator: Heart Rate Zones
- Heat index
- How hot it feels when humidity is combined with the air temperature.
- Calculator: Heat Index
- Hectare
- A unit of area equal to 10,000 square metres, about 2.47 acres.
- Calculator: Area Hectares To Acres
- Horsepower
- A unit of power; one mechanical horsepower equals about 745.7 watts.
- Calculator: Power Watts To Horsepower
- Hypotenuse
- The side opposite the right angle in a right triangle, found with the Pythagorean theorem.
- Calculator: Pythagoras Hypotenuse
I
- Ideal body weight
- A reference weight for a given height and sex from formulas such as Devine or Robinson, not a health target.
- Calculator: Ideal Body Weight
- Ideal gas law
- The relation PV = nRT between the pressure, volume, amount and temperature of a gas.
- Calculator: Ideal Gas Law
- Inflation
- The general rise in prices over time, which reduces what a fixed amount of money can buy.
- Calculator: Inflation
- Internal rate of return (IRR)
- The discount rate at which the net present value of all the cash flows of an investment equals zero.
- Calculator: Irr Approximation
K
- Kilowatt-hour (kWh)
- The energy used by a 1,000-watt load running for one hour, the unit on electricity bills.
- Calculator: Kwh From Watts
- Kinetic energy
- The energy of a moving object, equal to half its mass times the square of its speed.
- Calculator: Kinetic Energy
L
- Least common multiple (LCM)
- The smallest positive whole number that is a multiple of two numbers.
- Calculator: Lcm Two Numbers
- Litres per 100 km
- Fuel consumption measured as the litres a vehicle uses to travel 100 kilometres; lower is more efficient.
- Calculator: Fuel Consumption L100km
- Loan-to-value ratio (LTV)
- The loan amount divided by the appraised value of the property it finances.
- Calculator: Loan To Value
- Logarithm
- The power to which a base must be raised to give a number.
- Calculator: Logarithm Change Of Base
M
- Macronutrients
- The three nutrients that supply energy: protein and carbohydrates at 4 kcal per gram, fat at 9 kcal per gram.
- Calculator: Macronutrients
- Margin of error
- The range above and below a survey result within which the true value is likely to fall at a given confidence level.
- Calculator: Margin Of Error
- Marginal tax rate
- The rate of tax paid on the next dollar of income, as opposed to the average rate on all income.
- Calculator: Marginal Vs Effective
- Markup
- The amount added to cost to set a selling price, expressed as a share of the cost.
- Calculator: Markup Vs Margin
- Mean arterial pressure
- The average pressure in the arteries over one heartbeat, estimated from systolic and diastolic readings.
- Calculator: Mean Arterial Pressure
- Metabolic equivalent (MET)
- The energy cost of an activity as a multiple of the energy used sitting at rest.
- Calculator: Calories Burned Met
- Molarity
- The concentration of a solution in moles of solute per litre of solution.
- Calculator: Molarity
- Mortgage points
- Fees paid upfront to a lender, each equal to 1% of the loan, in exchange for a lower interest rate.
- Calculator: Mortgage Points
N
- Net present value (NPV)
- The sum of an investment's future cash flows discounted to today, minus its initial cost.
- Calculator: Net Present Value Single
- Newton
- The SI unit of force, the force that accelerates one kilogram by one metre per second squared.
- Calculator: Force Newtons To Pounds Force
O
- One-rep max (1RM)
- The heaviest load you can lift once with correct form, often estimated from several lighter repetitions.
- Calculator: One Rep Max
P
- Paint coverage
- The wall area one litre or gallon of paint covers in a single coat.
- Calculator: Paint Coverage Room
- Payback period
- The time it takes for the savings or income from an investment to repay its cost.
- Calculator: Payback Period
- Percent error
- How far a measured value is from the true value, as a percentage of the true value.
- Calculator: Percent Error
- Percentage change
- The difference between a new and an old value divided by the old value, times 100.
- Calculator: Percentage Change
- Percentile rank
- The percentage of values in a group that fall below a given value.
- Calculator: Percentile Rank From Counts
- pH
- The negative base-10 logarithm of the hydrogen ion concentration; below 7 is acidic, above 7 is basic.
- Calculator: Ph From Concentration
- Pounds per square inch (psi)
- A unit of pressure; one bar equals about 14.5 psi.
- Calculator: Pressure Bar To Psi
- Power factor
- The ratio of real power to apparent power in an AC circuit, between 0 and 1.
- Calculator: Power Factor Correction
- Present value
- What a future sum is worth today once discounted at a given rate.
- Calculator: Present Value Future Sum
- Price per square foot
- A property's price divided by its floor area, used to compare homes of different sizes.
- Calculator: Square Foot Price
R
- R-value
- A material's resistance to heat flow; the higher it is, the better the insulation.
- Calculator: Insulation R Value
- Rebalancing
- Buying and selling holdings to bring a portfolio back to its target allocation.
- Calculator: Portfolio Rebalancing
- Return on investment (ROI)
- The gain from an investment divided by its cost, expressed as a percentage.
- Calculator: ROI Calculator
- Rise and run
- The height of one stair step and its horizontal depth, which together set how comfortable a staircase is.
- Calculator: Stair Rise Run
- Roof pitch
- The steepness of a roof, given as the rise over a 12-unit run or as an angle.
- Calculator: Roof Pitch Angle
- Rule of 72
- A shortcut that estimates the years needed to double money by dividing 72 by the yearly rate in percent.
- Calculator: Rule Of 72
S
- Sales tax
- A tax added to the price of goods and services at the time of purchase, as a percentage of the price.
- Calculator: Sales Tax
- Simple interest
- Interest calculated only on the original principal, never on interest already earned.
- Calculator: Simple Interest
- Sleep cycle
- A sequence of light, deep and REM sleep lasting about 90 minutes that repeats through the night.
- Calculator: Sleep Cycles
- Specific heat
- The energy needed to raise one kilogram of a material by one degree Celsius.
- Calculator: Specific Heat
- Standard deviation
- A measure of how spread out values are around their mean, the square root of the variance.
- Calculator: Standard Deviation Population
T
- Total daily energy expenditure (TDEE)
- The calories you burn in a day, estimated as resting metabolism multiplied by an activity factor.
- Calculator: Calorie
V
- Value-added tax (VAT)
- A consumption tax charged as a percentage of the price at each stage of sale.
- Calculator: Vat Added
- VO2 max
- The highest rate at which your body can take in and use oxygen during exercise, in millilitres per kilogram per minute.
- Calculator: Vo2max Cooper
- Voltage drop
- The loss of voltage along a wire caused by its resistance, larger for long runs and thin wire.
- Calculator: Wire Voltage Drop
W
- Waist-to-hip ratio
- Waist circumference divided by hip circumference, a marker of how body fat is distributed.
- Calculator: Waist To Hip Ratio
- Waste factor
- The extra material, usually 5 to 15%, added to an order to cover cuts, breakage and mistakes.
- Calculator: Tile Count Waste
- Weighted average
- An average in which each value counts in proportion to its weight.
- Calculator: Weighted Average Two Groups
- Weighted average cost of capital (WACC)
- The average rate a company pays to finance itself, weighting the cost of debt and of equity by their shares.
- Calculator: Weighted Average Cost Of Capital
- Wind chill
- How cold it feels on exposed skin when wind is combined with the air temperature.
- Calculator: Wind Chill