TOPIC HUB · RESOURCES
Finance resources
A primary-source desk: verify rules and disclosures at CFPB, IRS, and Investor.gov, then open a How To Calculate sketch. Not another calculator playbook.
4 question rails · 7 official links · calculators stay free
Framing: agency-first source desk with question rails, not a mortgage PITI playbook and not a sky amber card dump.
Affiliate and partner disclosure
How To Calculate may earn a commission if you use a linked partner product in the future. Partner links will be labeled. Calculators stay free. We do not sell your calculator inputs. See disclaimers and editorial policy for the full rules. Disclaimers · Editorial policy.
Question → agency → tool
Four common finance questions. Verify on the official page first, then sketch numbers here.
01
Am I reading a mortgage disclosure correctly?
AGENCY
CFPB: Owning a homeLoan Estimate, Closing Disclosure, and shopping worksheets from the consumer bureau.
HTC TOOL
Mortgage calculatorSketch PITI and total interest after you understand the disclosure fields.
02
How do I compare an auto loan offer?
03
Is my withholding in the right ballpark?
AGENCY
IRS tax withholding estimatorOfficial federal withholding tool. Not a substitute for filing software or a tax pro.
HTC TOOL
Income tax calculatorEducational bracket and effective-rate sketch for planning conversations.
04
What does compound growth look like in an SEC teaching tool?
AGENCY
Investor.gov compound interestSEC Office of Investor Education calculator for classroom-style compounding.
Official and nonprofit sources
Bookmark these when a calculator result needs a statute, disclosure, or teaching definition.
- CFPB: Owning a homeMortgage shopping, disclosures, and homeowner rights.
- CFPB: Auto loansAuto financing terms and consumer tools.
- IRS: Tax withholding estimatorFederal withholding planning (not a filing substitute).
- IRS: Tax Topics indexPlain-language index of federal tax topics.
- Investor.gov: Compound interestSEC educational compound growth calculator.
- Investor.gov: Introduction to investingSEC investor education on accounts, risk, and fraud basics.
- Federal Reserve: Personal finance resourcesFed consumer and community finance education entry points.
On-site map
Topic hubs, glossary, formulas lab, and trust pages after you leave the agency site.
- Finance decision mapStart-here path and lanes for housing, loans, investing, tax, and cars.
- Mortgage hubPITI, affordability, amortization, rent vs buy playbook.
- Loans hubAPR, payment fit, total interest, auto and EMI tools.
- Investing hubContribution path, real return, retirement sizing.
- Taxes hubIncome tax sketches and marginal vs effective literacy.
- Finance glossaryDefinitions with calculator handoffs.
- Finance formulas labExpression peels for APR, PITI, DTI, real return, and more.
- Editorial policyHow we write, update, and correct calculator pages.
- DisclaimersEducational-use limits for tax, lending, and investing tools.
One caution
Agency sites are the source of truth for rules and disclosures. Our calculators are educational sketches that can lag statute or product changes. When a number decides a contract, use the official form and your lender, broker, or tax professional.