AWS has no fixed monthly price. A small production web app often runs about $150-400 a month, while larger workloads run into thousands. The reliable way to estimate yours is to list every part of your architecture, price it in the AWS Pricing Calculator, then add the costs calculators usually miss, like data transfer, NAT Gateways, and public IP addresses.
Most estimates aren't wrong because of bad math. They're wrong because they leave things out. This guide walks you through building an estimate that holds up when the first real bill arrives.
Key Highlights
AWS has two pricing calculators: a free public one that uses list prices, and one inside the Billing console that can apply your own discounts and commitments.
An accurate estimate starts with your architecture, not the calculator. Every component you forget is a gap in the estimate.
Networking costs are the most commonly missed part of an AWS estimate.
Treat the estimate as a starting point, and compare it against your real bill after the first month.
What Is the AWS Pricing Calculator?
The AWS Pricing Calculator is AWS's free cost estimation tool. You pick services, enter how much you expect to use, and it shows an estimated monthly cost. It comes in two versions.
The public calculator at calculator.aws needs no account and uses standard list prices. It's the right starting point for new projects.
The in-console calculator lives in the Billing and Cost Management console, under Budget and Planning, and has been generally available since May 2025. Because it knows your account, it goes further:
Workload estimates price a specific application or change, and they're available to every account type.
Bill estimates model your whole consolidated bill, starting from last month's usage. These are available only to management and standalone accounts.
Three rate options: before discounts, after discounts, or after discounts and commitments, so you can see what you'd actually pay.
Commitments: EC2 Reserved Instances and Compute and EC2 Instance Savings Plans are supported.
To import your historical usage, the in-console version needs Cost Explorer enabled.
How Do You Estimate AWS Costs Step by Step?
List every component of your architecture. Include compute, storage, databases, load balancers, networking, monitoring, and backups. If it's in your diagram, it's on your bill.
Choose your Region. Prices vary by Region, so price where you'll actually run.
Estimate your usage in billing units. That means hours per month (730 for always-on resources), GB stored, requests, and GB of data sent to the internet or between Availability Zones.
Enter each component in the calculator, grouped by environment: production, staging,g and development.
Add the costs estimates usually miss. These are covered in their own section below.
Compare pricing models. Price your steady baseline with Savings Plans or Reserved Instances as well as On-Demand, to see the realistic range.
Add a buffer for growth. Usage rarely stays flat. A 10-20% buffer is a sensible starting point for a new workload.
Check the estimate against your first real bill. Compare it in Cost Explorer after a month, then update it.
How Much Does AWS Cost per Month for a Small Startup?
Here's a priced example: a typical small production setup in us-east-1, at On-Demand list prices.
2 EC2 instances (t3.medium): 2 × $0.0416/hour × 730 hours = $60.74
60 GB of EBS gp3 storage for those instances: 60 × $0.08 = $4.80
Application Load Balancer: $0.0225/hour × 730 hours = $16.43, plus about $5.84 at light traffic (1 LCU) = $22.27
RDS PostgreSQL (db.t3.medium, Single-AZ): $0.072/hour × 730 hours = $52.56
1 NAT Gateway: $0.045/hour × 730 hours = $32.85, plus 100 GB processed at $0.045 = $37.35
Data transfer out: 200 GB, minus 100 GB free, × $0.09 = $9.00
S3 Standard storage: 100 GB × $0.023 = $2.30
3 public IPv4 addresses (the NAT and the load balancer): 3 × $0.005/hour × 730 hours = $10.95
Total: about $200 a month, before database storage, backups, monitoring, support, and tax.
Switching the database to Multi-AZ for high availability adds another $52.56, bringing the total to about $253. Notice how much of the bill isn't servers. The load balancer, NAT Gateway, IP addresses, and data transfer together cost more than the two instances.
Which Costs Do AWS Estimates Usually Miss?
These are the line items that most often turn a good estimate into a surprise bill:
Data transfer. Egress to the internet, traffic between Availability Zones, and replication between Regions all have their own per-GB rates.
NAT Gateways. An hourly fee plus a per-GB processing fee, charged on top of normal data transfer.
Public IPv4 addresses. Every one is charged hourly, including those on load balancers and NAT Gateways.
Logs and monitoring. CloudWatch log ingestion and storage grow with traffic.
Backups and snapshots. Storage for EBS snapshots and database backups adds up over time.
Support plans and tax. The calculator estimates costs before tax and only includes a support plan if you add one.
Non-production environments. Staging and development often run around the clock, even though nobody included them in the estimate.
Services you forgot. AWS notes that any service you don't include will make your estimate differ from your actual bill.
How Accurate Is the AWS Pricing Calculator?
The calculator's math is accurate for whatever you enter. The gap comes from what you don't enter, and from a few built-in assumptions:
The public calculator uses list prices, so it won't reflect any discounts or commitments you already have.
Workload estimates in the console assume no unused commitments are available to absorb the new usage. Commitments are modeled only in bill estimates.
It doesn't account for per-second billing on services that use it.
Estimates are in US dollars and before tax.
The best way to improve accuracy is to close the loop: once the workload is running, compare actual spend with the estimate using the native tools covered in this guide to AWS cost management.
Estimate or TCO: Which Do You Need?
An estimate answers "what will this workload cost on AWS each month?" A total cost of ownership analysis answers a different question: "Is running this on AWS cheaper than running it ourselves?" If you're comparing cloud with on-premises infrastructure, you need a full AWS TCO calculation, including staffing, hardware, and migration costs, not just a monthly estimate.
Conclusion
Estimating AWS costs comes down to completeness. The AWS Pricing Calculator handles the math, but only you can make sure every component, every environment,t and every networking charge is in the estimate. Start with your architecture diagram, price it at list prices, add what calculators miss, then compare against your first real bill and adjust. An estimate that gets checked after one month is worth far more than a perfect one that never gets revisited.
Want to see how your actual AWS spend compares to what you planned, broken down by service and team? Book a 30-minute demo and see how Opsolute connects your AWS bill to the architecture behind it.
FAQ
How accurate is the AWS Pricing Calculator?
It's accurate for the usage you enter at the rates it applies. Most gaps come from missing components, like data transfer, NAT Gateways, ys or non-production environments, and from list prices that don't reflect your discounts. The in-console version can apply your actual discounts and commitments.
How much does AWS cost per month for a small startup?
A small production web app often costs about $150-400 a month. A typical setup with two small EC2 instances, a load balancer, a small PostgreSQL database, a NAT Gateway, and modest traffic costs about $200 a month at On-Demand list prices in us-east-1, before backups, monitoring, support, and tax.
Which costs do AWS estimates usually miss?
Data transfer, NAT Gateway fees, public IPv4 addresses, CloudWatch logs, backups and snapshots, support plans, tax, and non-production environments that run around the clock.
Is the AWS Pricing Calculator free?
Yes. The public calculator is free, and so are workload estimates in the console. In-console bill estimates include five free estimates a month, with additional ones currently priced at $2 each.
Can the AWS Pricing Calculator include my Savings Plans or discounts?
Yes, in the in-console version. It can show estimates before discounts, after discounts, or after discounts and commitments, and it supports EC2 Reserved Instances and Compute and EC2 Instance Savings Plans. Commitments are modeled in bill estimates, not workload estimates.
