Tools
Tools
Each tool answers one decision question from figures you enter yourself, shows the formula it used, and states what it cannot tell you. The library is organised by the decision you are trying to make rather than by the arithmetic behind it.
Published tools
Before you invest
Investing
Investment Fee Drag Calculator
How much could fees reduce your future investment value?
Converts recurring percentage and fixed investment costs into a projected end-value effect under your own assumptions, and separates the amounts deducted from their compounding effect.
Investing
Opportunity Cost Calculator
What projected financial value do you give up by choosing one use of the same money over another?
Projects two uses of the same money over one horizon, under your own value-change assumptions, and reports the gap in ending value and where one path overtakes the other.
Investing
High-Water Performance Fee Calculator
A fee of X% of gains above a hurdle, subject to a high-water mark — what does that structure actually cost over a given run of returns?
Applies a hurdle and a high-water mark period by period over a return path you enter, and reports what the fee takes and what share of the gross gain that turns out to be.
Investing
Structured Payoff: Floor, Cap and Participation
How much upside does a floor actually cost, and where does holding the index directly pay more?
Computes a floor, cap and participation payoff for an index outcome you state, and marks where each bound begins to bind and where the structure and the index change places.
Real estate
Deposit Needed for the Next Price Band
How much more deposit reaches the next loan-to-value band, and what is that band actually worth?
Takes a price, a deposit, a term and the band table you are looking at, and splits the monthly saving into what the smaller loan buys and what the lower rate buys.
Investing
Dividend Withholding Drag at Two Rates
If two funds suffer different blended withholding rates, what is the difference worth over your horizon?
Sets two blended withholding rates against a gross dividend yield and reports what each takes a year, and what the difference between them has come to per unit of capital.
Investing
Contribution Limit When the Allowance Tapers
When an allowance tapers against income your own contribution enters, what is the largest contribution that fits?
Solves the circular limit exactly from your own figures, and reports how far it falls below the figure reached unaided and whether the arrangement has a solution at all.
Investing
Currency Drag on Overseas Dividends and Trades
What is a platform’s currency spread costing you a year across overseas dividends and trades?
Splits the annual currency cost into the dividend leg and the two trading legs, and reports the dividend yield at which it outweighs the annual fee you are ranking it against.
Investing
Reinvestment Charge Against One Dividend
Below what dividend size is a reinvestment charge taking more of the payment than you would accept?
Prices one reinvestment against your platform’s charge structure, and reports the smallest dividend that stays inside the share of a payment you will accept losing.
After a loss
Investing
Drawdown Recovery Calculator
How much must an investment gain after a loss, and how long could recovery take under the assumptions you enter?
Turns a loss into the gain needed to reverse it, and separates regaining the old balance from catching the plan the portfolio was on before it fell.
Investing
Bond Fund Break-even Calculator
How long must a bond fund be held before higher yields repay the fall in its price?
Finds the holding period at which a rate move has been repaid, publishing the single-rise and the repeating-rise horizons together because sources answer one without saying which.
Is the growth real?
Investing
Real Return after Fees and Inflation Calculator
Your balance grew, but did your purchasing power grow after fees and inflation?
Projects a nominal balance after your own fee assumptions, translates it into start-date purchasing power, and compares it with the inflation-adjusted value of every amount contributed at the date it was contributed.
Investing
Leverage Decay Horizon Calculator
Over what holding period does a fund with a daily multiple stop delivering that multiple?
Measures how long a daily-multiple fund takes to fall a shortfall you choose behind the multiple of its underlying, with the causes of the gap kept separate rather than merged.
Debt and personal finance
Marginal Rate Inside a Benefit Withdrawal Band
What does a benefit withdrawn above a threshold add to the rate on your next unit of income?
Reports what one unit of the benefit adds to the marginal rate inside the band and what the whole benefit adds, because the effective rate scales with the number of units.
Investing
Extra Tax When Accumulated Income Was Never Recorded
Income was taxed inside your holding every year and you never recorded it. What does that cost in extra tax when you sell?
Works out what the missing records actually cost at a disposal, where the usual answer overstates it, and after how many years it starts to matter.
Can you absorb a shock?
Debt and personal finance
Emergency Fund Runway Calculator
How long can your usable liquid buffer cover the monthly shortfall in this scenario?
Counts only the liquid resources you would genuinely use, nets off the income that continues, and reports how many months of shortfall the remainder covers.
Debt and personal finance
Paying a Premium Monthly, as an Annual Rate
A quotation prices monthly payment as a percentage of the whole premium. What is that as an annual rate?
Reads an instalment quotation back as the annual rate it is really charging, from four figures printed on the quotation, and sets the stated uplift beside it.
Investing
Waiting Out a Redemption Gate
If everyone asks at once, how long does a gated fund take to return the share you would count as out?
Reports the wait in dealing periods and in days for the share you would count as having got your money out, and what is still in the fund when the schedule ends.
Debt and personal finance
Write-Off Shortfall Over a Finance Term
If the vehicle is written off, how far short does the insurer’s settlement fall of what the lender is owed?
Traces the gap between settlement and finance balance month by month: when it opens, how large it gets and when it closes, at each of two depreciation rates rather than one.
Debt and personal finance
Lump Sum to the Liability Line, and the Cheaper Exit
Have you reached the line that lets you hand the vehicle back, and is paying up to it cheaper than settling?
Tests an agreement against the share of the total amount payable that voluntary return requires, and costs three ways out of it side by side from your own figures.
Business
Settlement When a Loss Outlasts the Indemnity Period
If the recovery outlasts the indemnity period, how much of the loss is actually inside the policy?
Truncates the loss at the indemnity boundary, applies average and the limit to what remains, and reports all four reductions separately rather than as one settled figure.
Debt and personal finance
Cost of Floating a Refundable Sum to a Deadline
You pay a sum now and get it back later, unless a deadline passes first. What does the wait cost, and what does missing it cost?
Prices both outcomes of a refundable sum from your own figures: what carrying it costs by the month you expect it back, and what missing the deadline would cost on top.
Does the property carry itself?
Real estate
Rental Break-even and Cushion Calculator
How much can go wrong before the rental starts costing you money?
Nets vacancy, owner costs and debt service against a scheduled rent to find where monthly cash flow reaches zero, and excludes purchase price and gross yield by design.
Does the advertised yield survive costs and dilution?
Crypto and DeFi
Staking Yield after Fees and Token Dilution Calculator
After reward fees and token-supply growth, are you gaining relative ownership or only receiving more tokens?
Applies reward fees to the rewards rather than to the balance, then divides the resulting token growth by your own supply-growth assumption to report what happened to your share.
Crypto and DeFi
Liquidity Provision Fee Break-even Calculator
How much fee income does a pooled two-asset position need before it beats simply holding the two amounts?
Reports the fee income, as a share of the position, at which a rebalanced two-asset position matches having held the two amounts, and the price moves a given fee income covers.
Does the business model work?
Business
Markup vs Margin Calculator
What margin does a price or a markup actually produce once fees and per-order costs are counted?
Reconciles price, markup, gross margin and contribution margin, and shows the per-unit bridge that percentage fees and per-order costs open between them.
Business
Repayment Multiple as an Annual Rate
An arrangement quotes a multiple rather than a rate. What is repaying 1.4 times what you take as an annual rate?
Converts a quoted repayment multiple into an implied annual rate over the term the arrangement itself implies, and settles the same multiple at four other repayment speeds.
Business
Turnover Past a Registration Threshold
What does the first unit of turnover past a registration threshold cost, and how far does the loss run?
Shows what crossing costs on turnover already earned, and how wide the range is over which more turnover leaves a business worse off than stopping short of the threshold.
How long does the pot last while you are drawing on it?
Investing
Withdrawal Fee and Pot Depletion Calculator
What is the percentage fee as a share of the income I am drawing, and how much sooner does the pot run out because of it?
Runs the same pot, withdrawal and return twice, once with your annual fee and once without, and reports the fee as a share of the income drawn and the months of income it costs.
What a UBWHY tool does, and what it never does
A calculator that returns a number and stops is not useful for a decision. Every tool here shows its formula and its event order, separates what was actually deducted from what the model derived, states the assumptions it made on your behalf, and links to an explainer that teaches the mechanism without needing your figures at all.
- No tool reaches a verdict about a product, a provider or a platform.
- No tool carries an affiliate link, a referral code or a sponsored placement, and the registry behind these pages has no field that could hold one.
- No tool prefills a market return, a benchmark fee or a "typical" anything.
- No tool stores what you enter. The calculation runs in your browser; UBWHY does not receive the values, writes them to no cookie and no storage, and places them in no URL.
- No tool gives financial, legal or tax advice, or knows anything about your circumstances.
The library is being built out. Tools appear here when they are finished, tested and reviewed, never as a placeholder for something that does not exist yet.