Calculator methodology

Shared conventions across numeric tools

Each calculator on North Horizon runs its own calculation in your browser. They share a few conventions so the outputs are internally consistent — but they are not linked to a single retirement-style engine like some specialist sites use.

When you enter an annual return or interest rate, we convert it to a monthly rate by dividing by 12. For example, 12% per year becomes 1% per month. Some other calculators use an effective monthly rate of roughly 0.95% instead, which compounds back to slightly more than 12% over a year. Over long horizons that difference adds up.

When cash flows are assumed to happen

• SIP, step-up SIP and goal-planner contributions are made at the start of each month, before that month's return is applied. This is an annuity-due pattern — each instalment earns one extra month of growth compared with end-of-month investing.
• SWP withdrawals: the remaining balance earns one month of return first, then the withdrawal is taken from what is left.
• Loan EMI: each month, interest is calculated on the opening balance, then the principal component of the EMI reduces the balance. The standard amortising-loan formula is used for the EMI itself.
• Step-up SIP increases and SWP withdrawal step-ups are applied once every twelve months, after the twelfth instalment at the previous level.
• Goal-planner inflation compounds once per year on the goal cost, not month by month.

Rounding and display

• All arithmetic runs at full floating-point precision inside the calculation.
• Rupee amounts are rounded to the nearest whole rupee only when shown — using the Indian numbering format (lakhs and crores where relevant).
• Because we round for display, adding up figures in a table by hand may occasionally differ from a total shown by a rupee or two.

SIP calculator

The tool loops month by month: add the contribution, then grow the balance by the monthly rate. Total contributions, illustrative growth and estimated value are the outputs.

There is no step-up, no lump-sum top-up and no change in contribution mid-way unless you change the inputs yourself.

Step-up SIP calculator

Same monthly loop as the SIP calculator, but the monthly contribution increases once per year — either by a fixed rupee amount or by a percentage of the current contribution.

The yearly schedule table shows the contribution level at the start of each year and the total contributed in that year.

Goal planner

• Future goal cost = today's cost × (1 + inflation rate)^years, with inflation applied annually.
• Existing savings are projected forward as a lump sum at the assumed investment return, compounded monthly.
• Planned monthly contributions use the standard annuity-due future-value formula at the same assumed return.
• The shortfall is future goal cost minus projected savings and contributions.
• Indicative monthly required divides the funding gap (goal minus grown savings) by the annuity-due factor. Additional monthly required is the gap between that figure and what you already entered.
• This is a sizing illustration — not a product recommendation or a guarantee that the goal will be met.

SWP calculator

Starting from your opening corpus, each month the balance grows at the monthly rate, then the withdrawal is taken (capped at whatever remains).

If the balance reaches zero before the period ends, the tool records the month of depletion and stops further withdrawals.

An optional annual step-up increases the monthly withdrawal once per year. Yearly snapshots show opening balance, withdrawals, illustrative growth and closing balance.

Loan EMI calculator

EMI uses the standard amortising formula: principal × monthly rate × (1 + monthly rate)^n ÷ ((1 + monthly rate)^n − 1), where n is tenure in months.

At zero interest, EMI is simply principal ÷ months.

The yearly breakdown allocates each EMI payment to interest and principal using the opening balance each month. Actual lender schedules, fees or prepayment terms may differ.

Emergency fund calculator

Target = essential monthly expenses × months of cover you choose. Gap = target minus existing savings (never shown below zero).

No inflation, return or tax is applied — this is a simple sizing guide, not a cash-flow projection.

Risk profile assessment

• Ten questions across risk capacity, risk requirement, risk tolerance and time horizon. Each answer carries a score from 0 to 3.
• Dimension scores are each question's total divided by the maximum possible for that dimension, expressed as a percentage.
• The overall blended score combines 60% of the average across all questions with 40% of the lowest dimension score — so a weak area pulls the result down.
• Profile bands (Conservative through Aggressive) map from the blended score in steps of 20 points.
• This is educational framing only. It does not recommend a specific fund, asset allocation or portfolio.
• If you complete the optional lead step and submit, your answers may be sent to us through the risk-profile API and stored for follow-up. Until then, answers stay in your browser session only.

Financial health check

• Ten self-assessment questions across four pillars: Foundation, Protection, Planning and Investing.
• Each answer uses a score from 0 to 2. Per-pillar verdicts (Strong, Needs Attention, Priority) come from the average score in that pillar — not from a single overall number.
• Nothing is stored or transmitted. Refreshing the page clears your answers.
• Verdict labels describe areas to think about — not a diagnosis, credit score or product pick.

Other numeric calculators

Lumpsum, retirement, FIRE, income, inflation, EPF, NPS, gratuity and similar tools use the same monthly compounding (annual rate ÷ 12) and nearest-rupee display as the SIP and SWP calculators, unless a note on the tool says otherwise.

Retirement corpus needed is the present-value of inflated annual expenses over the retirement years at the drawdown return you enter — a level annuity. It is not a 4% rule unless you choose inputs that match one.

CAGR is (end ÷ start)^(1 ÷ years) − 1. XIRR uses Newton–Raphson on an initial outflow, optional monthly outflows and a final inflow.

Gratuity uses 15/26 × last monthly salary × completed years, with a ₹20 lakh exemption cap in the illustration. EPF uses 12% employee contribution, employer 12% split with 8.33% EPS on a ₹15,000 wage ceiling. NPS exit is illustrated as 60% lump sum and 40% annuity — a commonly cited picture, not a live PFRDA quote.

Real return is (1 + after-tax nominal) ÷ (1 + inflation) − 1. The market-crash tool applies a one-time fall to the opening corpus, then the usual SWP path.

What these tools deliberately do not do

• No market volatility — returns are applied smoothly every month at the rate you entered.
• No sequence-of-returns stress testing — a fall early in retirement or near a goal is not modelled separately from a fall later.
• No tax on redemptions, capital gains, TDS or surcharge unless you mentally adjust the inputs yourself.
• No exit loads, expense ratios, transaction costs or stamp duty — enter a net-of-cost return if you want the output to be closer to reality.
• EPF, NPS and gratuity tools use simplified, commonly cited formulas. Statutory rates, ceilings, exit rules and tax treatment change — they are not payroll, PF or tax computations.
• No product selection — nothing here tells you what to buy, sell or hold.

Where your data goes

Numeric calculators run entirely in your browser. Inputs are not sent to us unless you separately submit a contact or risk-profile form.

The financial health check does not collect or store answers.

The risk profile assessment may store answers locally in your browser session and, if you choose to submit the optional follow-up step, send them through our risk-profile endpoint for a conversation request.

Corrections

If you believe a calculation on this site is wrong, we want to know. Write to us with the inputs you used and the result you expected, and we will check it, fix it if it is wrong, and note the change on this page.