# Financial Modeling Blog

In-depth guides on financial modelling, valuation, forecasting, and Excel.

Canonical: https://finamodel.com/blog

- [The Rule of 72: Quick Mental Math for Growth and Investing](https://finamodel.com/blog/rule-of-72-explained) - The Rule of 72 formula, exactly how accurate it is by rate, and how to use it as a rule of 72 calculator sanity-check on growth and doubling-time assumptions in a financial model. (2026-09-16, 9 min)
- [Liquidation Preferences: 1x, Participating and Stacked](https://finamodel.com/blog/liquidation-preferences) - A practical guide to liquidation preferences: what the 1x and 2x multiples mean, participating vs. non-participating preferred, participation caps, how a preference stack pays out across multiple funding rounds, and when investors convert to common stock. (2026-09-15, 12 min)
- [Cash-on-Cash Return: Formula and Example](https://finamodel.com/blog/cash-on-cash-return) - Learn the cash-on-cash return formula for real estate, how leverage changes it, and a fully worked apartment-building example comparing all-cash, financed, and IRR. (2026-09-14, 11 min)
- [How to Underwrite a Multifamily Acquisition](https://finamodel.com/blog/multifamily-underwriting-model) - A step-by-step guide to multifamily underwriting: build the rent roll, calculate NOI, check the going-in cap rate, size debt and test DSCR, model the value-add plan, and underwrite the exit - with a fully worked 150-unit example. (2026-09-13, 14 min)
- [How to Model Synergies in an M&A Deal](https://finamodel.com/blog/synergies-in-ma) - Learn how to model synergies in M&A: build cost and revenue synergies bottom-up, risk-adjust and phase them in, net out integration costs, and discount to NPV to test against the deal premium. (2026-09-12, 13 min)
- [How to Build an Income Statement Projection](https://finamodel.com/blog/income-statement-projection) - Learn how to build an income statement projection line by line - revenue, COGS, operating expenses, EBIT, and net income - with Excel formulas and a full worked example. (2026-09-11, 12 min)
- [Compound Interest Formula: How It Works in Financial Modeling and Excel](https://finamodel.com/blog/compound-interest-in-modeling) - The compound interest formula explained term by term, with worked examples across annual, quarterly, monthly and continuous compounding, the Excel functions, and how it becomes the discount factor in a DCF. (2026-09-10, 13 min)
- [Pre-Money vs Post-Money Valuation Explained](https://finamodel.com/blog/pre-money-vs-post-money-valuation) - Pre-money vs post-money valuation, explained with the core math: how to calculate post-money valuation three ways, a full worked cap-table example, the option pool shuffle that lowers your effective pre-money, and the mistakes that cost founders real ownership. (2026-09-09, 12 min)
- [EBITDA Bridge: How to Build One in Excel](https://finamodel.com/blog/ebitda-bridge) - Learn how to build an EBITDA bridge in Excel: decompose the year-over-year change in EBITDA into volume, price, cost, and FX drivers, and turn it into a waterfall chart. (2026-09-05, 12 min)
- [How to Build an OpEx Forecast](https://finamodel.com/blog/opex-forecasting) - How to build an opex forecast in Excel: the five cost behaviours, the right forecast method for each (run-rate, headcount-driven, percent-of-revenue, driver-based, zero-based), a monthly six-category worked example, and a budget-vs-actual variance report. (2026-09-04, 13 min)
- [CAPM and Cost of Equity: Formula and Worked Example](https://finamodel.com/blog/capm-cost-of-equity) - Learn how to calculate the cost of equity with the CAPM formula: the risk-free rate, equity risk premium, beta (levered and unlevered), the size premium, and a full worked example. (2026-09-03, 13 min)
- [Net Operating Income (NOI): Formula and How to Calculate It](https://finamodel.com/blog/net-operating-income-noi) - Learn how to calculate Net Operating Income (NOI) for real estate: the formula, what's included above vs. below the line, NOI vs. EBITDA, a worked self-storage example, and stabilized vs. pro forma NOI. (2026-09-02, 12 min)

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