Financial Calculator User Guide
AMRT · Amortization
Choose an instruction to see the matching keys and values. Practice separately in the real calculator.
Open financial calculator ↗Worked examples
Know the mode controls
Analyze PM1–PM2 from N, I%, PV, PMT and payment settings. BAL is ending balance; INT/PRN apply to PM1, while ΣINT/ΣPRN total the range.
Review these controls before choosing a case. Keystroke steps show menus opening, selection and closure.
BAL · Open lesson
BAL · Balance — Output: remaining loan balance after payment PM2.
1. Organize the inputs
Balance and interest over the first 12 payments
Borrow 100,000 at nominal 5%, paying 1,000 monthly, N=120. Use P/Y=C/Y=12, END, and analyze payments 1–12.
| Variable | Input | Action |
|---|---|---|
| PM1 | 1 | EXE |
| PM2 | 12 | EXE |
| N | 120 | EXE |
| I% | 5 | EXE |
| PV | 100,000 | EXE |
| PMT | -1,000 | EXE |
| BAL | Unknown | Select → SOLVE |
2. Follow the keystrokes
Steps 1–6
Steps 7–12
Steps 13–15
3. Show answer and interpretation
amount
BAL follows payment 12. INT and PRN refer to payment 1; ΣINT and ΣPRN total payments 1–12.
4. Avoid these mistakes
- PM1 starts at 1; PM2 must be ≥PM1 and ≤N, and cannot extend past payoff. Payments must amortize. PMT is negative; balance keeps the positive principal sign.
- Finish input with EXE before solving. Clear or changed inputs/settings invalidate earlier results; calculate again.
5. Practice it yourself
The link opens a separate calculator tab. It does not fill, clear or change your calculator's inputs; follow the settings and rows above.
Practice in the financial calculator (new tab) ↗ΣINT · Open lesson
ΣINT · Total interest — Output: interest paid from PM1 through PM2 inclusive.
1. Organize the inputs
Balance and interest over the first 12 payments
Borrow 100,000 at nominal 5%, paying 1,000 monthly, N=120. Use P/Y=C/Y=12, END, and analyze payments 1–12.
| Variable | Input | Action |
|---|---|---|
| PM1 | 1 | EXE |
| PM2 | 12 | EXE |
| N | 120 | EXE |
| I% | 5 | EXE |
| PV | 100,000 | EXE |
| PMT | -1,000 | EXE |
| ΣINT | Unknown | Select → SOLVE |
2. Follow the keystrokes
Steps 1–6
Steps 7–12
Steps 13–15
3. Show answer and interpretation
amount
BAL follows payment 12. INT and PRN refer to payment 1; ΣINT and ΣPRN total payments 1–12.
4. Avoid these mistakes
- PM1 starts at 1; PM2 must be ≥PM1 and ≤N, and cannot extend past payoff. Payments must amortize. PMT is negative; balance keeps the positive principal sign.
- Finish input with EXE before solving. Clear or changed inputs/settings invalidate earlier results; calculate again.
5. Practice it yourself
The link opens a separate calculator tab. It does not fill, clear or change your calculator's inputs; follow the settings and rows above.
Practice in the financial calculator (new tab) ↗INT · Open lesson
INT · Interest — Output: interest portion at payment PM1, using cash-outflow signs.
1. Organize the inputs
Interest — manual workflow
Analyze a 100,000 loan repaid at 1,000 per period. Given PM1=1 · PM2=12 · N=120 · I%=5 · PV=100000 · PMT=-1000, use the settings below to find INT manually.
| Variable | Input | Action |
|---|---|---|
| PM1 | 1 | EXE |
| PM2 | 12 | EXE |
| N | 120 | EXE |
| I% | 5 | EXE |
| PV | 100,000 | EXE |
| PMT | -1,000 | EXE |
| INT | Unknown | Select → SOLVE |
2. Follow the keystrokes
Steps 1–6
Steps 7–12
Steps 13–15
3. Show answer and interpretation
amount
Interest: -416.6666666666667. Output: interest portion at payment PM1, using cash-outflow signs.
4. Avoid these mistakes
- PM1 starts at 1; PM2 must be ≥PM1 and ≤N, and cannot extend past payoff. Payments must amortize. PMT is negative; balance keeps the positive principal sign.
- Finish input with EXE before solving. Clear or changed inputs/settings invalidate earlier results; calculate again.
5. Practice it yourself
The link opens a separate calculator tab. It does not fill, clear or change your calculator's inputs; follow the settings and rows above.
Practice in the financial calculator (new tab) ↗PRN · Open lesson
PRN · Principal — Output: principal portion at payment PM1, using cash-outflow signs.
1. Organize the inputs
Principal — manual workflow
Analyze a 100,000 loan repaid at 1,000 per period. Given PM1=1 · PM2=12 · N=120 · I%=5 · PV=100000 · PMT=-1000, use the settings below to find PRN manually.
| Variable | Input | Action |
|---|---|---|
| PM1 | 1 | EXE |
| PM2 | 12 | EXE |
| N | 120 | EXE |
| I% | 5 | EXE |
| PV | 100,000 | EXE |
| PMT | -1,000 | EXE |
| PRN | Unknown | Select → SOLVE |
2. Follow the keystrokes
Steps 1–6
Steps 7–12
Steps 13–15
3. Show answer and interpretation
amount
Principal: -583.3333333333333. Output: principal portion at payment PM1, using cash-outflow signs.
4. Avoid these mistakes
- PM1 starts at 1; PM2 must be ≥PM1 and ≤N, and cannot extend past payoff. Payments must amortize. PMT is negative; balance keeps the positive principal sign.
- Finish input with EXE before solving. Clear or changed inputs/settings invalidate earlier results; calculate again.
5. Practice it yourself
The link opens a separate calculator tab. It does not fill, clear or change your calculator's inputs; follow the settings and rows above.
Practice in the financial calculator (new tab) ↗ΣPRN · Open lesson
ΣPRN · Total principal — Output: principal paid from PM1 through PM2 inclusive.
1. Organize the inputs
Total principal — manual workflow
Analyze a 100,000 loan repaid at 1,000 per period. Given PM1=1 · PM2=12 · N=120 · I%=5 · PV=100000 · PMT=-1000, use the settings below to find ΣPRN manually.
| Variable | Input | Action |
|---|---|---|
| PM1 | 1 | EXE |
| PM2 | 12 | EXE |
| N | 120 | EXE |
| I% | 5 | EXE |
| PV | 100,000 | EXE |
| PMT | -1,000 | EXE |
| ΣPRN | Unknown | Select → SOLVE |
2. Follow the keystrokes
Steps 1–6
Steps 7–12
Steps 13–15
3. Show answer and interpretation
amount
Total principal: -7162.665703442617. Output: principal paid from PM1 through PM2 inclusive.
4. Avoid these mistakes
- PM1 starts at 1; PM2 must be ≥PM1 and ≤N, and cannot extend past payoff. Payments must amortize. PMT is negative; balance keeps the positive principal sign.
- Finish input with EXE before solving. Clear or changed inputs/settings invalidate earlier results; calculate again.
5. Practice it yourself
The link opens a separate calculator tab. It does not fill, clear or change your calculator's inputs; follow the settings and rows above.
Practice in the financial calculator (new tab) ↗Supported results and operating manual
Targets across the lessons: BAL · ΣINT · INT · PRN · ΣPRN
AMRT · Operating manual
- Enter N, I%, PV, PMT and payment interval PM1/PM2 (starting at 1, PM2 ≥ PM1).
- Select BAL, INT, PRN, ΣINT or ΣPRN and SOLVE.
- Loan proceeds are positive and payments negative.
- Use consistent TVM rate and payment settings.
Keys and settings
Keys and workflow
- ↑↓ selects the active row. The highlighted row is the variable you are editing.
- Enter a number or expression (500*6 or 10000*(1.05)^10), then EXE to evaluate, store and advance. Dates use date input instead of expressions.
- SOLVE calculates the selected unknown/output from the other known values. MATH uses EXE only.
- CLR clears the draft while editing; otherwise it clears only the selected stored variable. Backspace recalls a stored value and deletes its last character, then EXE stores the change. Escape cancels a draft and restores the original value. After EXE advances, select the field you want to change. Clearing a stored input invalidates dependent results. Selecting a read-only result or history row leaves it untouched; settings and MATH history are preserved. MENU offers current-mode clear and calculator reset.
Settings: P/Y is payments per year; C/Y is compounding per year. BEGIN/END selects beginning/end-of-period payments for TVM and AMRT. N counts payment periods, not years. Enter 5 for 5%.
MENU → Fill Example provides working inputs for the current mode. N/A or an error means the inputs/settings do not support a valid result; check the highlighted field and domain restrictions.
Need help with signs or EXE/SOLVE? Read FAQ