From purchasing power to market equilibrium.

Inflation

Estimate how inflation changes the future price of an amount over time.

Purchasing power

Estimate what today's money may buy after inflation reduces its purchasing power.

Salary vs inflation

Compare a salary change with inflation to see whether real pay rose or fell.

Required salary

Calculate the future salary needed to preserve today's purchasing power.

Real interest rate

Compare nominal interest with inflation using approximate and exact Fisher calculations.

Real investment return

Adjust a nominal investment return for inflation and estimate real ending value.

Business economics

Break-even

Find the unit sales needed to cover fixed and variable costs.

Margin

Calculate gross profit and margin from revenue and cost.

Markup

Calculate markup from unit cost and selling price.

Contribution margin

Measure how much sales revenue remains after variable costs.

Microeconomics

Price elasticity

Calculate arc price elasticity and classify demand as elastic or inelastic.

Price change revenue

Estimate how a price change could affect quantity demanded and revenue using an elasticity assumption.

Consumer surplus

Calculate consumer surplus for a linear demand curve.

Market equilibrium

Solve equilibrium price and quantity for linear supply and demand equations.

Tax incidence

Estimate how a per-unit tax is divided between consumers and producers using elasticities.

Macroeconomics

GDP growth

Calculate the percentage change in GDP between two periods.

GDP deflator

Calculate the GDP price deflator from nominal and real GDP.

Fiscal multiplier

Explore the textbook government-spending multiplier from the marginal propensity to consume.