ERP Cost Calculator: Custom ERP Build and Running Costs

A custom ERP with several modules, dashboards and integrations costs $25,750–$51,500 from a US freelancer (median $36,800) and $44,150–$88,350 from a US agency (median $63,100). That is the "full product" scope of the Project Cost Estimator web app engine, and it is where a multi-module ERP for a small or mid-sized business lands.

A single-module tool, such as inventory or order management on its own, fits the simple scope: $16,100–$32,200 from a freelancer (median $23,000). A manufacturing or multi-entity ERP with real-time stock, forecasting or AI features fits the enterprise scope: $36,300–$72,600 from a freelancer (median $51,850) and $62,300–$124,600 from an agency (median $89,000).

The calculator above runs the web app niche. Pick a scope and a market and it returns both bands, the weeks and the monthly running cost. Off-the-shelf ERP licences are set by their vendors and are not priced here; the comparison section shows how to weigh them.

Web app niche, US market. The ERP column maps each engine scope to the kind of system it buys.

At the US custom-development freelancer median of $135 an hour, the engine’s medians imply about $23,000 / $135 ≈ 170 hours for one module, $36,800 / $135 ≈ 273 hours for the multi-module system and $51,850 / $135 ≈ 384 hours for the enterprise scope.

Those are first versions. ERPs grow: most businesses add a module or an integration every year after launch.

1. Number of modules. Each module (inventory, purchasing, sales, production, HR, finance) is its own set of screens, rules and reports.

1. 2. Integrations. Accounting software, e-commerce stores, shipping carriers, banks and payroll. Every integration needs mapping, error handling and a test account on the other side.
2. Data migration. Moving years of products, customers and open orders out of spreadsheets or an old system is often the most underestimated part.
3. Business rules. Approval chains, costing methods, units of measure, lot and serial tracking. Each rule is simple; there are always more than expected.
4. Roles and permissions. A warehouse user, a buyer, an accountant and a manager see different screens.
5. Reporting. Standard dashboards are part of the full product scope. Custom reports per department add hours.
6. Real-time and offline. Barcode scanning on a warehouse floor with poor signal, live stock across locations and forecasting move the build to the enterprise scope.

Engine medians for the two larger scopes, USD. Western Europe and Eastern Europe are one band each; South Asia covers India, Pakistan and Bangladesh.

The weeks do not change by market; the hourly rate does. An offshore ERP build saves the most money of any scope because it is the most hours. It also carries the most risk if the team does not understand your operations, so budget your own people’s time for workshops and testing.

The agency premium on the full product is $63,100 − $36,800 = $26,300 at the median. For an ERP, continuity matters more than for most software: the system runs the business every day. If you hire a freelancer, insist on documentation, a shared repository and a second developer who has seen the code.

Off-the-shelf ERP (cloud suites and open-source systems) charges licence or subscription fees per user or per module, set by each vendor, plus implementation by a partner. We do not price those licences here; get them from the vendors in writing.

To compare, put both on the same three-year basis:

1. 1. Custom: build median + 36 months of running cost + developer time for changes. For the US full product with a freelancer, before changes: $36,800 + $176 x 36 = $36,800 + $6,336 = $43,136.
2. Off-the-shelf: vendor licences for your user count x 36 months + implementation hours x the partner’s rate + yearly upgrades.

Off-the-shelf wins when your processes are standard and you can adapt to the software. Custom wins when the way you work is the advantage, when per-user licences get expensive at your headcount, or when you need one or two modules, not a suite. A middle route is common: an off-the-shelf core with a custom module for the part that is unique.

The engine puts running cost at $176/mo for the simple and full product scopes and $236/mo for the enterprise scope: hosting, tools and routine upkeep. Year one, at US medians:

Add developer time for changes. A 20-hour monthly block with a US freelancer at the median is 20 x $135 = $2,700 a month.

1. List the modules you need in the first version. One module is the simple scope; three to five is full product; manufacturing, multi-entity or forecasting is enterprise.

1. 2. Pick that scope and the market of the team you will hire in the calculator above.
2. Divide any quote by the team’s hourly rate and compare the hours with the figures above. Hourly rates by market are in the rate database.
3. Ask each team how they will migrate your data and who tests it.
4. For other kinds of business software, see the web app development cost page, the software development cost calculator or the main calculator.

Build bands, weeks and running cost: Project Cost Estimator engine, calibrated against 600+ project quotes and public rate benchmarks across 6 markets. Hourly rates (source: Clutch Apr 2026, Talmatic Global Snapshot, Arc.dev, Upwork medians, TechReviewer — calibrated to real 2026 agency/freelancer benchmarks). All figures in USD.

• - Methodology: https://projectcostestimator.com/methodology
• Rate database: https://projectcostestimator.com/rate-database

Figures used, US web app niche (freelancer / agency): MVP / simple CRUD $16,100–$32,200 ($23,000) / $27,600–$55,250 ($39,450); full product $25,750–$51,500 ($36,800) / $44,150–$88,350 ($63,100); enterprise $36,300–$72,600 ($51,850) / $62,300–$124,600 ($89,000). Full product medians by market: UK and Australia $32,700 / $54,950; Western Europe $28,650 / $50,350; Eastern Europe $14,250 / $28,650; South Asia $8,550 / $17,250. Enterprise medians: UK and Australia $46,100 / $77,500; Western Europe $40,350 / $71,000; Eastern Europe $20,050 / $40,350; South Asia $12,000 / $24,300. US custom-code freelancer rate $135. Agency premium $26,300. Running $176/mo and $236/mo; $2,112 and $2,832 a year; three years $6,336; three-year custom total $43,136. Year one $38,912, $65,212, $91,832. Retainer $2,700.