AI Subscription Cost Calculator (Monthly & Annual, LKR)

The calculator is pure arithmetic over a dated price table, no model, no account, no network call. Every AI vendor publishes a list price in US dollars per seat, either per month or per year. The tool turns your selection into one number you can actually budget against: the combined monthly and annual spend in rupees.

1. Per-subscription cost

For each tool you pick, with a chosen billing cycle and seat count, the effective monthly and yearly cost are:

• Monthly billing: monthly USD × seats; yearly = monthly USD × 12 × seats.
• Annual billing: yearly = annual USD × seats; effective monthly = annual USD ÷ 12 × seats.

Annual prices are only used where the vendor publishes a distinct annual list price (for example Claude Pro at $204 a year, an effective $17 a month). Where no annual plan exists, ChatGPT Plus and Pro, Claude Max, Gemini, Microsoft Copilot Pro and SuperGrok among them, annual billing is simply 12× the monthly price, so no saving is asserted that the vendor does not actually offer. The annual saving on a line is max(0, monthly × 12 − annual list) × seats, which is zero by construction on every plan without a published annual price.

2. Convert to rupees

Each US-dollar figure is multiplied by the USD→LKR rate. The field defaults to the Central Bank of Sri Lanka indicative rate of Rs 305 per dollar, last checked on 2026-06-05, and you can edit it to match your own card's rate. The conversion is LKR = USD × rate. The CBSL indicative rate is a mid-market reference, not the rate a bank gives you; if you want today's figure before you type one in, the currency converter carries a live USD/LKR rate.

3. Optional 18% VAT

The VAT (Amendment) Act No. 4 of 2025 brought services supplied by non-resident persons through electronic platforms into the Sri Lankan VAT net from 1 October 2025, at the standard 18% rate. When you turn the VAT toggle on, the tool adds base × 18% as a separate line so the pre-VAT figure stays visible, then shows the VAT-inclusive total. It is a toggle rather than a default because whether the charge reaches your card depends on whether that particular vendor has registered for Sri Lankan VAT, and because a VAT-registered business recovers it as input tax instead of bearing it. For the registered and reverse-charge cases in detail, the digital services VAT calculator works the invoice through properly.

4. Combine, compare, and cross-check

The combined monthly total is the sum of every line's effective monthly cost; the combined annual total is the sum of each line's yearly outlay. The tool also reports how much annual billing already saves you, how much more you could save by switching your remaining monthly lines to annual, the cheapest and most expensive tool in your stack, and an internal cross-check: the annual total recomputed from the monthly figures (Σ effective monthly × 12) must equal the sum of yearly outlays to the cent. The two methods always agree, the same idea as reconciling a tax figure against the regulator's own formula.

5. Edge cases and limits

Bad input never produces a plausible-looking wrong number. Seats must be a whole number from 1 to 100 and the rate must fall between Rs 50 and Rs 2,000 per dollar; anything else returns a specific message naming the field rather than a total. An empty selection is not an error, the totals stay at a clean Rs 0 with an empty state, never NaN. The cheapest and most expensive comparison is suppressed below two lines, where it would be meaningless. Large stacks stay finite: ChatGPT Pro at $200 a month across 100 seats at Rs 2,000 per dollar is Rs 480 million a year, computed exactly.

6. What this tool deliberately does not model

Three things sit outside it. It does not price per-token API usage, which is a different cost shape entirely, that belongs to the AI API cost calculator. It does not decide whether a flat subscription beats metered API access for your volume; the subscription vs API break-even calculator finds the crossover point. And it does not know your bank's markup, which is the next section, because the rate field is where you put it.

The list price is in US dollars. The debit on your statement is in rupees, and the two are separated by three things the vendor never shows you.

The issuer's rate, not the CBSL rate. Card networks convert at their own wholesale rate on the settlement date, which is close to but not identical to the Central Bank indicative rate, and the settlement date can be a day or two after you clicked subscribe.

A foreign-transaction markup. Most Sri Lankan issuers add a percentage on cross-border transactions, commonly in the region of 1–3%, disclosed in the card's tariff sheet rather than on the charge itself. It compounds every month you keep the subscription.

Rate drift over a year. A twelve-month commitment is twelve exposures to the rupee, not one. Annual billing converts the whole year at a single rate, which is a saving when the rupee weakens and a cost when it strengthens, a real consideration on top of the vendor's own discount.

The practical way to handle all three at once: find one past foreign charge on your statement, divide the rupee amount by the dollar amount, and enter that number as the rate. At Rs 305 mid-market plus a 2.5% markup, the effective rate is about Rs 312.63, which turns a $20 subscription from Rs 6,100 a month into Rs 6,252, and adds about Rs 1,830 over a year for that one tool alone.

All five use Rs 305/USD (illustrative; the live tool defaults to the CBSL rate and lets you override it). VAT off unless stated.

List prices in US dollars per seat, re-confirmed against each vendor's pricing page on 2026-06-05. “Annual” shows the total billed per year when an annual plan exists; otherwise annual billing is 12× the monthly price.

The optional VAT line applies 18% on top per the Inland Revenue Department's rule on non-resident electronic services.

• OpenAI: ChatGPT pricing (Plus, Pro, Team)
• Anthropic: Claude pricing (Pro, Max)
• Google: AI plans (Gemini AI Pro, AI Ultra)
• GitHub: Copilot plans (Pro, Pro+)
• Cursor: pricing (Pro, Ultra)
• Midjourney: subscription plans
• Central Bank of Sri Lanka: indicative USD/LKR exchange rate
• Inland Revenue Department: VAT on electronic services

All vendor prices and the USD/LKR reference were last re-confirmed against the sources above on 2026-06-05. AI subscription prices and tiers change often. These are illustrative reference figures for budgeting, not live quotes. Confirm the current price on the provider before you subscribe.