Annuity due is a stealth raise
Paying or receiving at the start of each period is like getting one extra period of interest. Annuity-due results are just ordinary-annuity results × (1 + r).
Annuity PV discounts a stream of equal (or growing) payments to today; FV rolls them forward to the end. Choose ordinary for end-of-period payments or due for beginning. Growing annuities use a payment growth rate g. The tool converts your annual rates to effective per-period values based on your chosen period unit.
Break-even shows when you cover fixed costs: units = Fixed / (Price − Variable Cost). Margin is (Price − Cost)/Price, while Markup is (Price − Cost)/Cost. They’re related but not the same—25% markup equals 20% margin.
Annuity PV/FV and Break-Even / Margin / Markup are everyday finance tools for planning payments, savings, and pricing. This guide explains what each term means, when to use it, and the key formulas our calculator applies. Examples use generic currency (apply £, $, € as needed).
An annuity is a stream of equal payments at regular intervals (monthly, quarterly, yearly). You’ll meet two timing types:
Present Value (PV) discounts future payments back to today; Future Value (FV) compounds payments forward. In our tool, you enter an annual rate; we convert it to an effective per-period rate based on your chosen unit (year/quarter/month).
Example: Pay 100 per month for 36 months at 8% annually. The tool converts 8% to an effective monthly rate and returns PV (today’s value of the stream) and FV (value at month 36). If you select “Annuity Due,” both results increase because cash arrives earlier.
Tips: If r ≈ g in a growing annuity, PV is very sensitive—try small adjustments to test robustness. For zero rates, the formulas simplify to arithmetic sums.
Use this side of the tool to sanity-check pricing and volume goals.
Conversions: from margin m to markup u = m / (1 − m); from markup u to margin m = u / (1 + u).
Example: Price 50, Variable Cost 30, Fixed Costs 10,000 → Contribution = 20. Break-even units = 10,000 / 20 = 500. Margin = 20 / 50 = 40%. If you plan 700 units, expected profit ≈ 700 × 20 − 10,000 = 4,000.
Pro tip: run quick sensitivities—nudge the rate, growth, price, or costs by ±5% to see how PV, FV, and break-even respond. Robust plans change slowly under small tweaks.
Paying or receiving at the start of each period is like getting one extra period of interest. Annuity-due results are just ordinary-annuity results × (1 + r).
In a growing annuity, when the discount rate and growth rate nearly match, PV becomes hypersensitive—change either by 0.1% and the value can jump.
Doubling a markup doesn’t double the margin: a 25% markup is a 20% margin; a 50% markup is a 33% margin. Conversions curve, not climb in lockstep.
Cutting variable cost by £1 can drop break-even units dramatically when contribution is thin; the same £1 cut barely matters if contribution is already wide.
The annuity formulas assume equal payments, but a lump sum today that equals the PV will grow to the same FV—two very different cash-flow shapes, same math bridge.