Rule of 40

The level of revenue at which total costs equal total income, resulting in neither profit nor loss. For growth businesses, understanding break-even informs decisions about pricing, unit economics, and the capital required to reach profitability.

The set of key performance indicators specifically designed to measure the health, growth, and unit economics of Software-as-a-Service businesses. Core SaaS metrics include annual recurring revenue (ARR), monthly recurring revenue (MRR), customer acquisition cost (CAC), lifetime value (LTV), churn rate, net revenue retention (NRR), and the Rule of 40.

EBITDA expressed as a percentage of revenue, indicating how much operating profit a company generates from each pound of revenue before non-cash charges and financing costs. EBITDA margin is a key benchmark for operational efficiency across industries.

A measure of a company's financial performance that calculates the value created above the required return of investors, defined as net operating profit after tax minus the cost of capital employed. EVA highlights whether a firm's intangible and tangible assets are generating returns that exceed their cost of capital.

The annualised value of recurring subscription revenue. ARR is the primary top-line metric for SaaS and subscription businesses, providing a normalised view of predictable revenue that strips out one-time fees and variable charges.

A software distribution model in which applications are hosted by a service provider and made available to customers over the internet on a subscription basis. SaaS businesses are characterised by recurring revenue, high gross margins, and significant intangible asset value in software and customer relationships.

Earnings Before Interest, Taxes, Depreciation, and Amortisation. A widely used measure of a company's core operating performance that strips out financing decisions, tax jurisdictions, and non-cash charges, making it useful for comparing profitability across companies.

A situation in which one party in a transaction possesses more or better information than the other, creating an imbalance that can affect pricing and deal outcomes. Information asymmetry is particularly acute in intangible-heavy businesses, where the true value of assets such as proprietary data, know-how, and relationships is difficult for external parties to assess.

SaaS Intangible Assets: ARR, Churn, and Customer Value

SaaS businesses generate value through intangible assets that compound over time — customer relationships measured by ARR and retention, technology platforms that scale without proportional cost, and data assets that improve with usage. Understanding the intangible asset composition of a SaaS business changes how you value it.

What is the Rule of 40?

The Rule of 40 states that a company's growth rate plus profit margin should total 40% or more — companies scoring below 40% risk unsustainable unit economics or insufficient growth.

What is the Quick Ratio in SaaS and why does it matter?

Quick Ratio measures (NRR × growth rate) / magic number, indicating whether a SaaS company's revenue growth is efficient and sustainable.

What is expansion MRR and contraction MRR?

Expansion MRR is new revenue from existing customers (upsells, cross-sells, seat expansion). Contraction MRR is lost revenue from downgrades, seat reductions, or feature cancellations.