About MilMath
MilMath is a free, no-signup library of military pay, benefits, and retirement calculators paired with plain-English guides. Service members shouldn't need a finance degree to understand a housing allowance or to compare two retirement systems. Our goal is to turn the rules buried in pay tables and regulations into clear numbers you can act on — without an account, a paywall, or a single piece of personal data leaving your browser.
What MilMath Is
We build focused, single-purpose tools that each answer one real question. Right now that includes a BAH Differential Calculator for comparing housing allowances between duty stations, a High-3 vs BRS Calculator for weighing the legacy and Blended Retirement systems side by side, and a VA Combined Rating Calculator that applies the VA's combined-ratings table and bilateral factor. Alongside each tool we write explainers that define the terms, show the math, and point to where the underlying rules come from.
Who It's For
MilMath is built for the people who actually live with these numbers: active-duty service members planning a PCS or a reenlistment, reservists and National Guard members tracking drill and benefit eligibility, veterans estimating disability compensation, and the military families making decisions around all of it. Whether you're a brand-new enlistee or close to a 20-year retirement, the tools are meant to be readable on your phone and useful in minutes.
How the Calculators Work
Each calculator runs entirely in your browser using published rates and formulas — for example, the combined-rating tool follows the VA's prescribed rounding and combination method rather than simply adding percentages. You enter your inputs, the math happens locally, and nothing is stored or transmitted. That keeps your information private and means the results are reproducible: the same inputs always produce the same numbers, so you can check our work.
Our Editorial Approach
We treat accuracy as the product. When a calculator depends on a rate or rule, we trace it back to the authoritative source — pay and allowance figures from DFAS, disability and benefit rules from the VA, and retirement and savings mechanics from the TSP and DoD — and we link to those sources so you can verify them yourself. MilMath is educational, not official guidance: we are an independent project and are not affiliated with the Department of Defense, DFAS, the VA, or any government agency. Our outputs are estimates intended to help you ask better questions, not to replace your finance office, command, or a qualified advisor.
Our Editorial Standards
- Accuracy. We update tools to reflect current rates and regulations, show the underlying math, and correct errors quickly. If you spot something wrong, tell us.
- Sourcing. Numbers and rules are grounded in official references (DFAS, VA, TSP, DoD) and linked, so claims are checkable rather than taken on faith.
- No paywall, no signup. Every calculator and guide is free, requires no account, and processes your inputs in your browser. See our privacy practices for details.
— The MilMath Team