Build vs Buy Software Calculator

Description

Free tool Build vs Buy Calculator

Keep paying for a subscription, or have the software built? Enter your own numbers to see the cumulative cost of each option over five years and the year the build breaks even. No email needed.

1 · Buying: the subscription

Price per user per month (₹)

Number of users

Expected yearly price increase %

Your own expectation. Leave at 0 if you have none.

One-off setup cost (₹)

Onboarding, migration, configuration.

2 · Building: custom software

Custom build cost (₹)

Prefilled with the cost model's base for a custom web application. Get your own range from the Software Cost Estimator and replace it.

Yearly maintenance % of build

Default is the middle of WavX's published 15–25% band. Charged from year two.

Enter every amount in the same currency. The ₹ sign is a label and nothing is converted. The calculator runs in your browser and does not submit what you type.

Break-even

Enter the subscription price and the number of users to see the comparison.

Request a project estimate Arithmetic on your own numbers, not a quote or a forecast.

The formula

The calculator works out two running totals and compares them year by year.

subscription total after year n = setup cost + the sum, for each year 1 to n, of (price per user per month × users × 12 × (1 + yearly increase) year − 1 )

build total after year n = build cost + (build cost × maintenance % × (n − 1))

break-even = the first year in which the build total ≤ the subscription total

Maintenance is charged from year two. Year one is treated as covered by the build, the same convention the WavX cost model uses for its three-year cost tables. If your builder charges for maintenance from the first month, add a year of it to the build cost. The table shows years one to five, and the calculator looks as far as year ten for a break-even.

Which numbers are yours and which are WavX's

Four of the six inputs are entirely yours: the subscription price, the number of users, the price increase you expect and the setup cost. The calculator suggests nothing for them, because a vendor's price list and your headcount are facts only you have.

Two fields arrive prefilled from the WavX cost model, and both can be overwritten. The build cost starts at ₹4,50,000 , the model's base figure for a custom web application. Maintenance starts at 20 % of build cost per year, the middle of the 15 – 25 % band in the maintenance cost guide . Use the Software Cost Estimator to get a planning range for your own scope, then run the low and the high end as two separate comparisons.

What the comparison leaves out

Fit. The sums assume both options do the job equally well. Whether they do matters more than the break-even year.

Time. A subscription is available today. A build takes weeks or months, and you may keep paying the subscription while it is built.

Growth. The number of users is held constant. If headcount is changing, rerun the comparison with the figure you expect.

Other running costs. Hosting and third-party services on the build side, add-ons and higher plans on the subscription side. Include them in the figures you enter if they are material.

Switching. Data migration and retraining apply in both directions and are not modelled.

Discounting. Totals are simple sums. Money spent in year five is counted the same as money spent today.

Reading the result

No break-even within ten years is a clear answer: on cost, keep the subscription. An early break-even is a reason to look more closely at a build, not a decision in itself. The guides on build vs buy software and custom software vs SaaS cover the side of the choice that is not arithmetic. If the thing you have outgrown is a spreadsheet, start with outgrowing Excel . WavX builds custom software and business systems , quoted after a conversation about scope.

Frequently asked questions

How is the break-even year calculated?

It is the first year in which the cumulative cost of the custom build (the build cost plus maintenance from year two) is less than or equal to the cumulative cost of the subscription (the setup cost plus every year's fees, including the price increase you entered).

Where does the default build cost come from?

From the WavX cost model. ₹4,50,000 is its base figure for a custom web application, before features, scale and design level. It is a placeholder: replace it with a range from the Software Cost Estimator or with a quote.

Does a break-even mean I should build?

Not on its own. The calculator compares cost and nothing else. If an off-the-shelf tool does the job, buying is usually simpler and faster. A build makes sense when ready-made tools do not fit how the business works and the cost comparison also holds up.