account_balanceCompound Interest & APY Tools · In-Browser Privacy

Consumer Liquid Capital Suite

Banking & Cash Accounts Calculators

Compare checking accounts, savings accounts, cash management tools, APR earnings, banking fees, overdraft costs, account yields, and cash optimization strategies with simple, free calculators.

searchkeyboard

account_balanceFlagship Cash Simulation Engine

Interactive Banking Optimizer & Fee Erosion Calculator

Quantify the combined cash leak from suppressed savings yields, unoptimized checking buffers, monthly maintenance charges, and predatory overdraft penalties.

tuneAccount Parameters

Average Checking Account Balance$3,500

Average Cash / Liquid Savings Balance$25,000

Traditional Checking APY0.01%

National average big-bank rate

High-Yield Cash / CMA APY4.60%

Top-tier online & broker sweep rate

Monthly Maintenance & ATM Fees

$/mo

Overdraft Incidents Per Year

@ $35/ea

1-Year Loss AuditCostly Friction

Total 1-Year Banking Wealth Drain

$1,520.65

Direct bank charges + missed yield on idle balances

Annual Lost Interest

$1,305.65

Opportunity cost

Direct Annual Fees

$215.00

Maintenance + Overdraft

5-Year Compounded CostAt 4.60% re-invested yield

$8,719.11

warning

Overdraft Equivalent APR Alert

A single $35 fee on an average $50 overdraft settled in 7 days equates to a staggering 3,650% APR!

5-Year Wealth TrajectoryOptimized vs Status Quo

Status Quo (Fees Drain Capital) High-Yield CMA (+4.60% APY Sweep)

Strategic Liquidity Architecture

4 Banking Rules Every Account Holder Must Know

Empirical patterns uncovered from checking and savings audits. Use these mental models to restructure everyday deposits.

cancel

Fee Trap Danger

The $12/Month Checking Trap

A recurring $12/mo maintenance charge completely wipes out the entire 1.00% annual interest on a massive $14,400 checking balance. Never pay monthly fees for retail transactions.

Threshold: $14.4k @ 1%See Fix →

price_change

Borrowing Math

The $35 Overdraft Reality

Overdraft protection is America's costliest short-term loan. Covering a $30 coffee run with a $35 fee paid back in 5 days translates to an effective APR exceeding 8,500%.

True APR: 1,000%+Calculate →

account_tree

Insurance & Sweep

CMA Multi-Bank Sweeps

Cash Management Accounts (CMAs) route capital across up to 20 partner banks, multiplying standard $250k FDIC limits into $2.5M–$5M of insured safety with instant liquidity.

FDIC: Up to $5,000,000Explore Sweeps →

shield

Buffer Optimization

The 1-Month Buffer Rule

Keep exactly 1.0 to 1.5 months of routine expenses in operational checking. Sweep 100% of residual cash into high-yield accounts on payday to avoid zero-yield drag.

Target Buffer: 30–45 DaysModel Inflows →

Instant Execution

12 Core Banking Calculators

Streamlined computational cards built for real-world personal banking decisions with zero peripheral clutter.

Net Yieldaccount_balance_wallet

Bank Account Calculator

Compare all-in net yield across checking and savings.

Calculate Now →

Cost Auditpayments

Checking Account Calculator

Calculate monthly maintenance and minimum balance costs.

Calculate Costs →

Growthtrending_up

Savings Account Calculator

Forecast interest earnings with compounding frequencies.

Calculate Growth →

Borrowing Ratepercent

APR Calculator

Determine nominal APR and effective annual borrowing cost.

Calculate APR →

Expense Auditreceipt_long

Bank Fee Calculator

Audit monthly maintenance, ATM, and transaction expenses.

Audit Fees →

Penalty Analysiswarning

Overdraft Calculator

Analyze overdraft fees and equivalent borrowing rates.

Analyze Overdraft →

Compounding APYcurrency_exchange

Account Yield Calculator

Convert APR to APY and calculate blended earnings.

Calculate Yield →

Sweep Protocolsync_alt

Cash Management Calculator

Optimize cash sweeps between checking and high-yield pools.

Optimize Cash →

Interest Simulationquery_stats

Bank Interest Calculator

Simulate daily, monthly, and annual compounding payouts.

Calculate Interest →

Wealth Erosiontrending_down

Fee Impact Calculator

Measure the long-term wealth erosion of account fees.

Calculate Impact →

Liquidity Flowwaves

Cash Flow Calculator

Map income vs. expense inflows and forecast minimum balances.

Map Cash Flow →

Benchmarkcompare

Account Comparison Calculator

Side-by-side comparison of online vs. brick-and-mortar accounts.

Compare Accounts →

Exhaustive Mathematical Suite

Complete Directory of 98 Banking Tools

86 Tools Available · 12 Clusters · All Models Local

account_balance

Checking Accounts

8 tools

Checking Account Calculatorarrow_forward Minimum Balance Fee Waiverarrow_forward High-Yield Checking APYarrow_forward Checking Direct Deposit Bonus ROIarrow_forward Debit Card Cashback Yieldarrow_forward Checking Buffer Optimizerarrow_forward Paper Check vs ACH Float Lagarrow_forward Business Checking Analysisarrow_forward

savings

Savings Accounts

8 tools

Savings Account Calculatorarrow_forward High-Yield Savings APY Forecasterarrow_forward Monthly Savings Target Planarrow_forward Emergency Fund Sizing Toolarrow_forward Federal Reserve Rate Cut Impactarrow_forward Certificate of Deposit (CD) Ladderarrow_forward Early CD Withdrawal Penaltyarrow_forward Sub-Savings Vault Allocatorarrow_forward

account_tree

Cash Management

7 tools

Cash Management Calculatorarrow_forward Brokerage Cash Sweep Yieldarrow_forward Multi-Bank FDIC Limit Sweep ($5M)arrow_forward CMA vs HYSA Fee-Yield Differentialarrow_forward Treasury Sweep vs Cash Fundarrow_forward Settlement Fund Idle Float Lossarrow_forward Uninvested Cash Drag Estimatorarrow_forward

percent

APR & Interest

9 tools

APR Calculatorarrow_forward APR to APY Conversionarrow_forward APY to APR Reverse Nominalarrow_forward Bank Interest Calculatorarrow_forward Daily Periodic Rate (DPR)arrow_forward Continuous Compounding Yieldarrow_forward 7-Day SEC Yield Converterarrow_forward Inflation-Adjusted Real Yieldarrow_forward Tax-Equivalent Bank Yield (TEY)arrow_forward

receipt_long

Banking Fees

9 tools

Bank Fee Calculatorarrow_forward Monthly Maintenance Fee Erosionarrow_forward Out-of-Network ATM Surchargearrow_forward Domestic & Wire Transfer Costarrow_forward Foreign Transaction Fee Analyzerarrow_forward Paper Statement Surchargearrow_forward Inactivity & Dormancy Chargearrow_forward Stop Payment Fee Comparisonarrow_forward Lifetime Banking Cost Projectionarrow_forward

warning

Overdraft Analysis

9 tools

Overdraft Calculatorarrow_forward Overdraft Equivalent APRarrow_forward NSF (Non-Sufficient Funds) Fee Costarrow_forward Overdraft Protection Line of Credit APRarrow_forward Opt-In vs Opt-Out Overdraft Exposurearrow_forward Extended Negative Balance Penaltyarrow_forward Overdraft Fee vs Payday Loan Costarrow_forward Linked Savings Transfer Fee Sizerarrow_forward Annual Overdraft Vulnerability Indexarrow_forward

compare

Account Comparison

6 tools

Account Comparison Calculatorarrow_forward Online vs Brick-and-Mortar Net Spreadarrow_forward Credit Union vs Commercial Bankarrow_forward Multi-Account Switch Benefit Scorearrow_forward Fintech Neobank vs FDIC Chartered Bankarrow_forward Interest Checking vs High-Yield Savingsarrow_forward

waves

Cash Flow Banking

6 tools

Cash Flow Calculatorarrow_forward Checking Minimum Balance Forecasterarrow_forward Payday Inflow-to-Outflow Synchronizerarrow_forward Bill Auto-Pay Protection Bufferarrow_forward Zero-Based Account Balancing Modelarrow_forward Semi-Monthly vs Bi-Weekly Cash Cadencearrow_forward

flag

Deposit Planning

6 tools

Deposit Target Date Calculatorarrow_forward Tiered Balance Rate Optimizerarrow_forward Initial vs Monthly Contribution Splitarrow_forward Tax Season Windfall Allocationarrow_forward Down Payment Escrow Growtharrow_forward Annual Deposit Milestone Trackerarrow_forward

military_tech

Yield Optimization

6 tools

Account Yield Calculatorarrow_forward Treasury Bill (T-Bill) vs HYSA Net Yieldarrow_forward State Tax Exemption Yield Deltaarrow_forward Blended Deposit Rate Calculatorarrow_forward Intro Promo Rate vs Long-Term Yieldarrow_forward Money Market Account (MMA) vs HYSAarrow_forward

devices

Digital Banking

6 tools

Instant Transfer Fee Sizer (Venmo/Zelle)arrow_forward Neobank Risk vs Yield Scorecardarrow_forward Digital Round-Up Spare Change Multiplierarrow_forward Virtual Card Cashback Aggregatorarrow_forward Direct Deposit Advance Cost (EWA APR)arrow_forward International Wire vs Wise/Remitly Deltaarrow_forward

hub

Personal Cash Architecture

6 tools

Hub-and-Spoke Banking Allocatorarrow_forward Joint vs Individual Deposit Sweeparrow_forward Self-Employed Tax Escrow Vaultarrow_forward Automated Payday Splitterarrow_forward Liquid Reserve Liquidity Ratioarrow_forward Family Trust Deposit FDIC Coveragearrow_forward

Comparative Analysis

Smart Banking Decisions: 8 Head-to-Head Matrices

Clear mathematical and structural distinctions between popular cash vehicles and account types.

Account Purpose

Checking vs Savings

Checking:Transactional utility, debit cards, unlimited debits, 0.01%–0.10% APY.

Savings:Capital preservation, interest generation, 4.00%–5.00% APY.

Verdict: Pair both via auto-sweep

Compounding Math

APR vs APY

APR (Nominal):Simple annual interest rate excluding the effect of compounding.

APY (Effective):True yield earned taking daily/monthly compounding into calculation.

Formula: APY = (1+r/n)ⁿ - 1

Platform Architecture

Online vs Traditional Bank

Online Bank:4.25%–5.00% APY, zero monthly fees, no physical teller branches.

Brick & Mortar:0.01% APY, cash deposits, notary in-person services, $12–$25 fees.

Spread: +$1,100+/yr per $25k

Custody & Insurance

CMA vs HYSA

CMA (Brokerage):Multi-bank sweep, checkwriting + SIPC + $2.5M+ FDIC aggregate.

HYSA (Direct Bank):Single bank charter, direct FDIC $250k single / $500k joint limit.

Advantage: CMA for high net worth

Short-Term Liquidity

Overdraft vs Credit Card

Bank Overdraft:Flat $35 fee on $50 negative = 3,650% effective annual rate.

Credit Card Charge:24.99% APR with 21–25 day grace period = $0.00 interest if paid on time.

Risk: Overdraft is 140x pricier

Wealth Impact

Bank Fees vs Opportunity Cost

Direct Charges:$15/mo maintenance fee = $180 annual visible out-of-pocket cash drain.

Opportunity Cost:Leaving $30k at 0.01% vs 4.60% = $1,377 hidden lost yield each year.

Insight: Lost yield exceeds fees 7:1

Institutional Safety

Digital Neobank vs Credit Union

Digital Neobank:Fintech intermediary relying on partner bank pass-through insurance.

Credit Union:Member-owned non-profit, direct NCUA insurance up to $250,000.

Safety: Direct NCUA/FDIC superior

Yield & Taxes

Idle Cash vs Liquid T-Bills

Bank Savings (HYSA):Subject to Federal + State + Local income tax on earned interest.

4-Week Treasury Bills:100% exempt from state & local taxes; federal backing.

Bonus: Saves 5%–13% state tax

Formula Codex

Banking Mathematics & Computational Formulas

The governing equations standardized under Truth in Savings Act (Regulation DD) and Consumer Financial Protection Bureau regulations.

Annual Percentage Yield (APY)Reg DD § 1030

APY = (1 + r / n)ⁿ - 1

Where r is the nominal stated APR as a decimal and n is the number of compounding periods per year (typically 365 for daily compounding in modern high-yield accounts).

Nominal Annual Percentage Rate (APR)Reg Z Standard

APR = n × [ (1 + APY)^{(1 / n)} - 1 ]

Derived by reversing compounding intervals. Used to extract the non-compounded contract borrowing or baseline annual interest quote from an advertised consumer yield.

Overdraft Equivalent APRTrue Cost

Overdraft APR = (Fee / Overdrawn Amount) × (365 / Days Negative) × 100

Demonstrates why single transaction overdraft penalties act as hyper-usurious short-term credit. A $35 charge on a $70 deficit cured in 3 days produces an annualized rate of 6,083.33%.

Compounded Fee Erosion (FV of Cost)Opportunity Cost

FV_fees = Fee × [ ((1 + r/12)^12t - 1) / (r/12) ]

Calculates the true future economic loss of recurring monthly bank fees by modeling what those charges would have grown to if left invested in an interest-bearing cash benchmark.

Programmatic Liquidity Matrices

Annual Interest Yield by Cash Balance & APY

Explore pre-computed annual returns across standard consumer cash thresholds with daily compounding.

Deposit Balance	Traditional (0.01%)	3.50% APY	4.00% APY	4.50% APY	5.00% APY
$500 Buffer	$0.05 / yr	$17.50 / yr	$20.00 / yr	$22.50 / yr	$25.00 / yr
$2,000 Working Cash	$0.20 / yr	$70.00 / yr	$80.00 / yr	$90.00 / yr	$100.00 / yr
$5,000 Emergency Fund	$0.50 / yr	$175.00 / yr	$200.00 / yr	$225.00 / yr	$250.00 / yr
$10,000 Cash Reserve	$1.00 / yr	$350.00 / yr	$400.00 / yr	$450.00 / yr	$500.00 / yr
$25,000 Liquid Pool	$2.50 / yr	$875.00 / yr	$1,000.00 / yr	$1,125.00 / yr	$1,250.00 / yr

David Sterling, CRPC®

verified

Lead Liquidity Auditor

20+ years specializing in cash sweep optimization, broker-dealer depository networks, and personal wealth preservation models.

Sarah Jenkins, CPA, CFP®

verified

Former FDIC Compliance Specialist

Expert on Regulation DD, Truth in Savings compliance, deposit insurance thresholds, and consumer fee transparency standards.

Frequently Asked Banking & Cash Questions

How much cash should I keep in checking vs high-yield savings?expand_more

Financial standard methodology suggests maintaining between 1.0 to 1.5 months of routine living expenditures in your operational checking account to safeguard against accidental overdrafts and accommodate billing float. Every dollar beyond this 30-to-45-day cushion should be automatically swept into a high-yield savings or cash management account earning top-tier APY (typically 4.0% to 5.0%+).

What is the actual mathematical difference between APR and APY in banking?expand_more

APR (Annual Percentage Rate) represents the nominal simple interest rate across a 365-day year without taking into account interest compounding. APY (Annual Percentage Yield) accounts for the frequency of compounding (daily, monthly, quarterly). Because daily compound interest generates interest on previously earned interest, an account with a 4.50% nominal APR compounded daily delivers an effective 4.60% APY.

How can a simple $35 overdraft fee equal over 1,000% APR?expand_more

APR calculates the cost of borrowing over an annualized duration. If your bank charges a $35 overdraft fee on a $50 negative balance and your direct deposit restores the balance in 7 days, you effectively paid $35 in interest for a 1-week $50 loan. Annualizing that 70% 7-day borrowing fee across 52.14 weeks yields an effective 3,650% APR.

Are Cash Management Accounts (CMAs) as safe as FDIC-insured banks?expand_more

Yes, provided the CMA uses an established program bank sweep. While the brokerage firm offering the CMA is protected under SIPC rather than FDIC, client cash is automatically swept into multiple participating chartered FDIC member institutions. This structure often allows CMAs to offer $2.5 million to $5 million in aggregate FDIC coverage (up to $250,000 per program bank), far surpassing standard bank caps.

Can checking account monthly maintenance fees be waived permanently?expand_more

Most brick-and-mortar banks waive their $10 to $25 monthly maintenance fee if you maintain a qualifying monthly direct deposit (usually $500 to $1,500) or keep a minimum daily balance ($1,500 to $5,000). However, modern online banks and Cash Management Accounts offer completely fee-free checking accounts with zero minimum balance requirements and no monthly maintenance charges under any circumstance.