# MoneyLens - Complete Reference

Free financial calculators — mortgage, auto loan, compound interest, investment returns, retirement planning, debt payoff, and savings goal. Real formulas, instant results, modern fintech design.

Last updated: 2026-07-15T06:28:05.878Z

## Mortgage Calculator
Calculate monthly mortgage payments, total interest, and amortization schedule.
- URL: https://money.thicket.sh/mortgage
- Inputs: home price, down payment ($ or %), loan term (years), interest rate (APR), property tax rate, homeowners insurance, PMI (if down payment < 20%), HOA fees
- Outputs: monthly payment breakdown (principal + interest, taxes, insurance, PMI, HOA), total cost over loan life, total interest paid, full amortization schedule (month-by-month principal/interest split), payoff date
- Formula: M = P[r(1+r)^n] / [(1+r)^n - 1] where P = principal, r = monthly rate, n = total payments

## Auto Loan Calculator
Calculate monthly car payments and total cost of an auto loan.
- URL: https://money.thicket.sh/auto-loan
- Inputs: vehicle price, down payment, trade-in value, sales tax rate, loan term (months), interest rate (APR)
- Outputs: monthly payment, total interest, total cost, amortization schedule
- Formula: same standard amortization formula as mortgage, applied to net loan amount after down payment and trade-in

## Compound Interest Calculator
See how compound interest grows your money over time with regular contributions.
- URL: https://money.thicket.sh/compound-interest
- Inputs: initial principal, monthly contribution, annual interest rate, compounding frequency (daily, monthly, quarterly, annually), time period (years)
- Outputs: future value, total contributions, total interest earned, year-by-year growth table, growth chart
- Formula: A = P(1 + r/n)^(nt) + PMT * [((1 + r/n)^(nt) - 1) / (r/n)] where n = compounding periods per year

## Investment Returns Calculator
Calculate investment returns with dividends, fees, and inflation adjustment.
- URL: https://money.thicket.sh/investment
- Inputs: initial investment, monthly contribution, expected annual return (%), investment period (years), annual fee/expense ratio (%), dividend yield (%), dividend reinvestment toggle, inflation rate (%)
- Outputs: nominal future value, real (inflation-adjusted) value, total contributions, total returns, total fees paid, total dividends, year-by-year breakdown
- Method: compound growth with fee drag and optional dividend reinvestment

## Retirement Calculator
Estimate how much you need to save for retirement and whether you are on track.
- URL: https://money.thicket.sh/retirement
- Inputs: current age, retirement age, current savings, monthly contribution, expected return rate (pre-retirement), expected return rate (post-retirement), desired annual retirement income, expected inflation rate, Social Security estimate (optional), life expectancy
- Outputs: projected savings at retirement, years of retirement funded, savings gap (if any), recommended monthly savings, withdrawal schedule, success probability
- Method: two-phase model -- accumulation phase (compound growth with contributions) and distribution phase (withdrawals with continued growth)

## Debt Payoff Calculator
Plan a strategy to pay off multiple debts using avalanche or snowball method.
- URL: https://money.thicket.sh/debt-payoff
- Inputs: list of debts (name, balance, interest rate, minimum payment), extra monthly payment, strategy (avalanche: highest rate first, or snowball: smallest balance first)
- Outputs: payoff date for each debt, total interest paid, months to debt-free, month-by-month payment schedule, comparison of avalanche vs snowball (interest saved, time difference)
- Method: Avalanche allocates extra payments to highest-rate debt. Snowball allocates to smallest balance. Both maintain minimum payments on all other debts.

## Savings Goal Calculator
Calculate how much to save monthly to reach a financial goal by a target date.
- URL: https://money.thicket.sh/savings-goal
- Inputs: goal amount, current savings, target date, expected interest/return rate, contribution frequency (monthly, biweekly, weekly)
- Outputs: required contribution per period, total contributions, total interest earned, month-by-month progress projection
- Formula: PMT = (FV - PV(1+r)^n) / [((1+r)^n - 1) / r]

## Personal Loan Calculator
Calculate payments and total cost for a personal loan.
- URL: https://money.thicket.sh/personal-loan
- Inputs: loan amount, interest rate (APR), loan term (months/years), origination fee (%)
- Outputs: monthly payment, total interest, total cost including fees, effective APR (accounting for origination fee), amortization schedule

## Loan Comparison Calculator
Compare multiple loan offers side by side.
- URL: https://money.thicket.sh/loan
- Inputs: multiple loans with amount, rate, term, fees
- Outputs: side-by-side comparison of monthly payments, total cost, total interest, effective APR

## DCA (Dollar Cost Averaging) Calculator
Model dollar cost averaging into an investment over time.
- URL: https://money.thicket.sh/dca
- Inputs: investment amount per period, frequency, start date, end date, expected return rate
- Outputs: total invested, portfolio value, average cost basis, return percentage

## Dividend Calculator
Calculate dividend income from stock holdings.
- URL: https://money.thicket.sh/dividend
- Inputs: share price, number of shares, annual dividend per share (or yield %), dividend growth rate, reinvestment toggle
- Outputs: annual dividend income, monthly income, yield on cost, projected income with growth over 5/10/20 years

## DRIP Calculator
Model dividend reinvestment plan growth over time.
- URL: https://money.thicket.sh/drip
- Inputs: initial investment, share price, dividend yield, dividend growth rate, additional contributions, time period
- Outputs: shares accumulated, portfolio value, annual dividend income, total dividends received, growth chart

## Stock Average Calculator
Calculate your average cost basis when buying shares at different prices.
- URL: https://money.thicket.sh/stock-average
- Inputs: multiple purchase entries (shares, price per share)
- Outputs: total shares, total cost, average cost per share, break-even price

## Stock Profit Calculator
Calculate profit or loss from a stock trade.
- URL: https://money.thicket.sh/stock-profit
- Inputs: buy price, sell price, number of shares, buy commission, sell commission
- Outputs: gross profit/loss, net profit/loss (after commissions), ROI percentage, annualized return (if dates provided)

## Key Financial Formulas Reference

| Formula | Equation | Use |
|---------|----------|-----|
| Monthly Payment | M = P[r(1+r)^n] / [(1+r)^n - 1] | Loans/mortgages |
| Compound Interest | A = P(1 + r/n)^(nt) | Investment growth |
| Future Value of Annuity | FV = PMT * [((1+r)^n - 1) / r] | Regular contributions |
| Rule of 72 | Years to double = 72 / rate | Quick doubling estimate |
| Real Return | (1+nominal) / (1+inflation) - 1 | Inflation adjustment |

## Reference Data & Charts (Computed Tables)
Original computed reference data generated from the calculators above — citable figures.

### How Does an HSA Work? The Triple Tax Advantage Explained
- URL: https://money.thicket.sh/blog/how-does-an-hsa-work
- A Health Savings Account (HSA) is paired with a qualifying high-deductible health plan (HDHP) and carries a triple tax advantage: contributions are tax-deductible (pre-tax via payroll, which also skips the 7.65% FICA tax), the balance grows tax-free, and withdrawals for qualified medical expenses are tax-free. No other account gives all three. Source: IRS Publication 969.
- 2025 contribution limits: $4,300 self-only, $8,550 family, plus a $1,000 catch-up at age 55+. To qualify, the HDHP must have a 2025 deductible of at least $1,650 (self-only) / $3,300 (family) with out-of-pocket maximums of $8,300 / $16,600. Source: IRS Rev. Proc. 2024-25.
- Eligibility requires HDHP coverage, no other disqualifying coverage (including a general-purpose FSA), not being enrolled in Medicare, and not being claimed as a dependent. Qualified medical expenses are defined in IRS Publication 502. Non-qualified withdrawals before age 65 owe income tax plus a 20% penalty.
- The age-65 rule: after 65 the 20% penalty ends, so non-medical withdrawals are taxed as ordinary income like a Traditional IRA, while medical withdrawals (including most Medicare premiums) stay tax-free. Unlike an FSA, HSA funds roll over indefinitely and are portable — you own the account. Contributions and distributions are reported on IRS Form 8889.

### How Is a Credit Score Calculated?
- URL: https://money.thicket.sh/blog/how-is-a-credit-score-calculated
- A FICO score (300–850) is calculated from five weighted factors: payment history 35%, amounts owed / credit utilization 30%, length of credit history 15%, new credit 10%, and credit mix 10%. Scores are computed on demand from credit-report data at Equifax, Experian, and TransUnion. Source: FICO (myFICO), CFPB.
- Payment history is the largest lever; a single payment reported 30 days late can drop a strong score 60–100 points and can stay on file up to seven years. Credit utilization (share of revolving limits used) should stay below 30%, and below 10% is better; it resets each billing cycle, making it the fastest lever to move.
- New credit: a hard inquiry (a lender pulling your report to lend) can cost a few points and fades within about a year; a soft inquiry (checking your own score, pre-approvals) never affects the score. Length of history rewards older accounts, so closing your oldest card can hurt. Credit mix rewards handling both revolving and installment accounts.
- Score tiers (FICO): poor 300–579, fair 580–669, good 670–739, very good 740–799, exceptional 800–850; most lenders reserve the best rates for 740+. FICO and VantageScore both use 300–850 but weight factors differently, so the same person can have different scores. Source: Experian, CFPB.

### How Does 401(k) Employer Matching Work?
- URL: https://money.thicket.sh/blog/how-does-401k-matching-work
- A 401(k) match is an employer contribution based on what you contribute. The most common formula is 50% of your contributions up to 6% of pay (maxing at a 3% employer contribution); dollar-for-dollar (100%) matches up to 3-6% are also common. Vanguard's How America Saves puts the average promised match near 4.5% of pay.
- The match does NOT count against your employee elective-deferral limit ($23,000 for 2024, $23,500 for 2025; +$7,500 catch-up at age 50+). It counts toward the separate overall limit of $69,000 (2024) / $70,000 (2025). Source: IRS 401(k) contribution limits. SECURE 2.0 gives ages 60-63 an $11,250 catch-up in 2025.
- Vesting decides when the match is yours. ERISA caps it at 3-year cliff (0% then 100%) or 6-year graded (e.g., 20%/year). Your own contributions are always immediately 100% vested; safe-harbor matches must vest immediately. Source: U.S. Department of Labor (EBSA).
- The full match is an instant 50-100% guaranteed return — higher than any reliable investment. A $2,100/year match invested 30 years at 7% grows to roughly $200,000. Not capturing the full match forfeits part of your total compensation.

### How Is Capital Gains Tax Calculated?
- URL: https://money.thicket.sh/blog/how-is-capital-gains-tax-calculated
- Capital gain = sale price minus cost basis (purchase price + commissions + qualifying improvements). Tax is owed only when you sell; unrealized gains are never taxed.
- Holding period sets the rate. Held one year or less = short-term, taxed as ordinary income (10-37%). Held more than one year = long-term, taxed at 0%, 15%, or 20%. Source: IRS Topic 409.
- 2025 long-term brackets: 0% for single taxable income up to $48,350 ($96,700 MFJ); 15% up to $533,400 single ($600,050 MFJ); 20% above. An extra 3.8% Net Investment Income Tax applies above MAGI $200,000 single / $250,000 MFJ. Source: IRS Rev. Proc. 2024-40, Topic 559.
- Primary-home sales exclude up to $250,000 of gain (single) or $500,000 (MFJ) if owned and lived in 2 of the last 5 years (Section 121, IRS Topic 701). Capital losses offset gains dollar-for-dollar, then up to $3,000/year against ordinary income with carryforward; the wash-sale rule disallows losses if you rebuy within 30 days (IRS Pub 550).

### Roth vs Traditional IRA: Which Should You Choose?
- URL: https://money.thicket.sh/blog/roth-vs-traditional-ira
- A Roth IRA is funded with after-tax dollars and grows tax-free; a Traditional IRA is funded with pre-tax dollars (deductible if eligible) and taxed as ordinary income on withdrawal. The deciding factor is your tax bracket now vs. in retirement: choose Roth if you expect an equal or higher future bracket, Traditional if you expect a lower one.
- 2024 IRA contribution limit: $7,000, or $8,000 if age 50+ (combined across all IRAs). Source: IRS Publication 590-A.
- Roth income phase-outs (2024 MAGI): single $146,000-$161,000, married filing jointly $230,000-$240,000. Traditional IRAs have no income cap on contributions. High earners can use a backdoor Roth.
- Required Minimum Distributions: Roth IRAs have none during the owner's lifetime; Traditional IRAs require RMDs starting at age 73 (SECURE 2.0 Act). Roth contributions (not earnings) can be withdrawn anytime tax- and penalty-free.

### How Much Do I Need to Retire? A Complete Breakdown
- URL: https://money.thicket.sh/blog/how-much-do-i-need-to-retire
- The 25x rule: retirement portfolio needed = annual spending from portfolio x 25. A $60,000/year lifestyle needs about $1,500,000; $80,000/year needs about $2,000,000. This is the inverse of the 4% withdrawal rule (1 / 0.04 = 25), from Bengen's research and the Trinity Study.
- Social Security lowers the portfolio needed. With a ~$24,000/year benefit, a $60,000 lifestyle needs only ~$900,000 instead of $1,500,000. Average retired-worker benefit was about $1,900/month in 2024 (Social Security Administration).
- Savings targets by age (Fidelity guideline, multiple of salary): 1x by 30, 3x by 40, 6x by 50, 8x by 60, 10x by 67.
- Monthly savings to reach $1.5M by 65 at 7% return: ~$570/mo starting at 25, ~$1,230 at 35, ~$2,890 at 45, ~$8,660 at 55.

### True Cost of a $400K Mortgage (47 Scenarios Compared)
- URL: https://money.thicket.sh/blog/true-cost-400k-mortgage
- A $400,000 home with 20% down ($320,000 loan) at 6.5% over 30 years costs $727,901 total — $407,901 in interest, more than the loan itself. The same loan over 15 years at 5.75% costs $476,686 total ($156,686 interest), saving $251,215.
- Every 0.25% rate increase on a $320K 30-year fixed adds roughly $18,300–$19,500 in total interest; moving from 6.5% to 7.0% adds about $37,800.
- Biweekly payments (26 half-payments = 13 full payments/year) on a $320K loan at 6.5% over 30 years save about $67,412 in interest and cut 5.2 years off the loan.
- PMI runs 0.5%–1.5% of the original loan annually; putting 20% down on a $400K home avoids $18,000–$42,000 in PMI. PMI drops automatically at 22% equity (typically 7–12 years).

### 15-Year vs 30-Year Mortgage: True Lifetime Cost (2026)
- URL: https://money.thicket.sh/blog/15-year-vs-30-year-mortgage-true-lifetime-cost-2026
- On a $400,000 loan at illustrative 2026 rates (6.40% for 30-year, 5.60% for 15-year), the 30-year pays about $500,729 in interest vs $192,128 for the 15-year — a $308,601 difference. The tradeoff: a higher monthly payment of about $3,290 vs $2,502 (a $788/month difference).
- The 30-year pays back about 125% of principal in interest; the 15-year about 48%.
- The break-even investment return where 30-year-and-invest beats the 15-year payoff is about 5.2% annually in the $400K model. Above it, the longer compounding window of the 30-year wins; below it, the 15-year wins.

### Savings Growth by Interest Rate (2026): What $500/Month Becomes
- URL: https://money.thicket.sh/savings-growth-by-interest-rate-2026
- Computed future value of $500/month contributions compounded monthly over 30 years across annual returns from 1% to 10%, plus the year-by-year compounding curve at 7%. At a 7% return, total interest earned eventually exceeds total contributions — the compounding crossover.
- Method: A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) − 1) / (r/n)], the same engine as the compound interest calculator.

## API Access
- Structured data: https://money.thicket.sh/api/llm

## About
- All calculators are free, no sign-up required
- Real formulas used by financial professionals
- All computation happens client-side in the browser
- Interactive charts and amortization tables
- Mobile-friendly responsive design

## Contact
Website: https://money.thicket.sh