Expression calculator
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Functions available: sqrt(x), ln(x), log(x) (base 10), exp(x), constants pi, e, Ans, Mem.
Percent is postfix: 12% → 0.12.
TVM worksheet
Sign convention is BA II style: typically **PV** opposite sign to **PMT** and **FV**. If solve fails, check signs.
Derived
Periodic i, EAR, quick rate sanity
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Amortization
Uses |PV| as principal, |PMT| as payment, and the computed periodic rate from I/Y.
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| # | Payment | Interest | Principal | Balance |
|---|
Explain What the TVM solver assumes
TVM solves the BA II style equation: PV(1+i)N + PMT·F(i,N) + FV = 0.
For BEGIN mode, payments are multiplied by (1+i). Rate conversion supports P/Y (payment frequency) and C/Y (compounding frequency).
Cash flows
| # | Cash flow (CF) | Repeat (F) | Action |
|---|
Row #0 is CF₀ at t=0. Rows after that are at t=1..
NPV
at the discount rate above
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IRR
periodic & annual equivalents
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Charts Cash flow bars + NPV profile
Cash flows by period
NPV profile (varies annual nominal rate)
Explain How NPV & IRR are computed
NPV uses the per-period discount rate:
i = (1 + (r/CY))CY/PY − 1,
then computes NPV = Σ CFt / (1+i)t.
IRR solves NPV(i)=0 via a bracketed root finder (robust bisection/secant hybrid). Multiple IRRs can exist when cash flows change sign multiple times.
Bond worksheet
Bump YTM
Rate fields accept % or bp (e.g. 25bp).
Price
clean • dirty • accrued
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Risk
duration • DV01 • convexity
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Explain Formula + conventions
Uses coupon frequency compounding (standard YTM convention). Dirty price is discounted cash flows from settlement:
Pdirty = Σ CFk / (1 + y/m)w + (k−1),
where m is coupon frequency, w is the fraction of a period until the next coupon.
Clean price = Dirty − Accrued Interest.
Cash flows & sensitivity
| # | Date | CF | t (periods) | PV |
|---|
Price–yield curve (clean price)
Notes What this worksheet is (and isn’t)
This is a plain‑vanilla fixed coupon bond model (no call/put, no odd first/last coupon, no stub periods).
For settlement/maturity alignment edge cases, validate against your desk system.