AWS Database Migration Service (DMS) is the AWS-native database replication tool for cloud migrations. It supports both homogeneous migrations (same engine on source and target, e.g. SQL Server on-premise to RDS for SQL Server) and heterogeneous migrations (different engine on source and target, e.g. Oracle to Aurora PostgreSQL with AWS Schema Conversion Tool). The pricing model is per-replication-instance per-hour, plus storage and standard data transfer. This page is the 2026 pricing reference for DMS specifically.
Short answer: AWS DMS itself is cheap, because the replication instance is the only meaningful charge and it bills per hour like EC2. A standard dms.r5.large replication instance runs $0.176 per hour (about $129 per month if left running); the free-tier dms.t3.micro is $0.0186 per hour; and DMS Serverless bills roughly $0.082 per DCU-hour (Single-AZ, US East). For a typical 5 TB database migration with a two-week change-data-capture window, the DMS tooling cost lands between about $60 and $565 depending on the instance class you pick, plus $12 to $58 of replication storage. The large costs in a database migration are almost never DMS itself; they are schema conversion labour (heterogeneous migrations) and any cross-region data transfer.
What AWS DMS costs by scenario, US East On-Demand (AWS DMS pricing structure, verified August 2026)
| Scenario | DMS mode | Tooling cost | Notes |
|---|---|---|---|
| Test / dev, under 100 GB | dms.t3.micro | $0, then ~$14/mo | Free tier: 750 hrs/mo (legacy) or $100+ credits (accounts after 15 Jul 2025) |
| Standard 5 TB, 2-week CDC | dms.r5.large (provisioned) | $60 to $250 | Plus $12 to $58 replication storage (gp2) |
| Long-running replication (weeks to months) | DMS Serverless | 15 to 35% less than provisioned | DCUs auto-scale; ~$0.082/DCU-hr Single-AZ |
| Very large / high-concurrency | dms.r5.24xlarge | $10.826/hr (~$7,800/mo) | 96 vCPU, 768 GB; rarely needed |
DMS cost rule of thumb
Pricing verification
AWS now sells DMS three ways, and the page you land on from a search usually only shows one of them. There are on-demand replication instances billed by the hour with no commitment, DMS Serverless billed per DCU-hour, and Database Savings Plans, which trade a committed hourly spend over a one or three year term for a lower rate. Separately, homogeneous data migrations (same engine on both ends, such as PostgreSQL to RDS for PostgreSQL) are billed by the hour for the duration of the migration only, with no replication instance to provision and therefore nothing to overprovision or scale by hand. Work out which of the four applies to your migration before comparing any hourly rate, because they are not quoted on the same basis. Source: the AWS DMS pricing page, with every rate on this page re-derived from the AWS Price List API offer file for us-east-1 (publication 11 September 2026), checked September 2026.
DMS provisioned pricing uses replication instance classes priced like EC2. Customers provision a replication instance (a specialised EC2 instance with the DMS replication engine installed), connect it to source and target endpoints, configure replication tasks, and pay for the instance plus its storage for the duration of the replication.
DMS provisioned replication instance pricing, US East, Single-AZ (AWS Price List API, August 2026)
| Instance class | vCPU | Memory | On-demand $/hour | Use case |
|---|---|---|---|---|
| dms.t3.micro | 2 | 1 GB | $0.0186 | Test and small migrations; free tier eligible |
| dms.t3.small | 2 | 2 GB | $0.0372 | Small databases under 100 GB |
| dms.t3.medium | 2 | 4 GB | $0.0745 | Standard small workloads |
| dms.t3.large | 2 | 8 GB | $0.149 | Mid-size workloads |
| dms.r5.large | 2 | 16 GB | $0.176 | Standard production migrations |
| dms.r5.xlarge | 4 | 32 GB | $0.353 | Larger production migrations |
| dms.r5.4xlarge | 16 | 128 GB | $1.411 | High-throughput, large databases |
| dms.r5.24xlarge | 96 | 768 GB | $10.826 | Very large or high-concurrency |
| dms.c5.large | 2 | 4 GB | $0.119 | CPU-intensive transformations |
| dms.c5.xlarge | 4 | 8 GB | $0.238 | CPU-intensive, larger workloads |
On top of the instance cost, DMS replication storage is charged at standard EBS rates (typically gp2 or gp3) for the replication state. Most production DMS migrations use 100 GB to 500 GB of replication storage, costing $11.50 to $57.50 per month at gp2 rates. Data transfer in to AWS is free; data transfer out (for example, replicating into a non-VPC target) is charged at standard egress rates documented on the AWS data transfer pricing page.
The eight replication instance families AWS publishes prices for in US East (N. Virginia) are t2, t3, c5, c6i, c7i, r5, r6i and r7i. The c7i and r7i families are the newest and are the ones missing from most DMS cost write-ups, which still quote the c5 and r5 generations. The practical rule: c6i costs the same per hour as the equivalent c5, and r6i the same as the equivalent r5, so moving to those generations is free. The 7th-generation c7i and r7i carry a modest premium (dms.c7i.large is $0.130 per hour against $0.119 for dms.c5.large, about 9 percent; dms.r7i.large is $0.190 against $0.176, about 8 percent).
Current-generation DMS replication instance rates, US East (N. Virginia), Single-AZ On-Demand (AWS Price List API, AWSDatabaseMigrationSvc us-east-1, publication date 31 August 2026)
| Instance class | vCPU | Memory | Single-AZ $/hour | Multi-AZ $/hour |
|---|---|---|---|---|
| dms.c6i.large | 2 | 4 GiB | $0.119 | $0.238 |
| dms.c6i.xlarge | 4 | 8 GiB | $0.238 | $0.476 |
| dms.c6i.4xlarge | 16 | 32 GiB | $0.952 | $1.904 |
| dms.c7i.large | 2 | 4 GiB | $0.130 | $0.250 |
| dms.c7i.xlarge | 4 | 8 GiB | $0.250 | $0.500 |
| dms.c7i.4xlarge | 16 | 32 GiB | $1.000 | $2.000 |
| dms.r6i.large | 2 | 16 GiB | $0.176 | $0.353 |
| dms.r6i.xlarge | 4 | 32 GiB | $0.353 | $0.706 |
| dms.r6i.4xlarge | 16 | 128 GiB | $1.411 | $2.822 |
| dms.r7i.large | 2 | 16 GiB | $0.190 | $0.380 |
| dms.r7i.xlarge | 4 | 32 GiB | $0.380 | $0.750 |
| dms.r7i.4xlarge | 16 | 128 GiB | $1.490 | $2.970 |
Multi-AZ replication instances are priced at roughly double the Single-AZ rate (AWS rounds some pairs, so a few classes come in a fraction under exact doubling). Replication storage doubles too: provisioned gp2 storage on a Single-AZ instance is $0.115 per GB-month and $0.23 per GB-month on Multi-AZ. On the burstable t3 classes, CPU credits consumed above the baseline are billed separately at $0.075 per vCPU-hour, which is why a t3.micro running a sustained full-load can bill well above its $0.0186 per-hour headline.
DMS Serverless is priced per DMS Capacity Unit hour rather than per instance hour. In US East the Single-AZ rate is $0.0819 per DCU-hour, so 1 DCU (2 GB of RAM) is $0.0819 per hour and the published 384 DCU maximum capacity is $31.4628 per hour. Multi-AZ Serverless is double: $0.1639 per DCU-hour, up to $62.9256 per hour at 384 DCU. The pricing is linear in DCUs, so there is no volume discount for provisioning a larger capacity range.
Where these rates come from
DMS Serverless was made generally available in 2023 and provides DMS replication as a pay-per-use service without instance provisioning. Pricing is per DCU (DMS Capacity Unit) per hour. DCUs scale automatically based on workload demand. The current Single-AZ Serverless rate in US East is approximately $0.082 per DCU-hour (Multi-AZ doubles it). A typical DMS Serverless replication for a 5 TB SQL Server migration uses 4 to 8 DCUs on average, costing roughly $8 to $16 per day of active replication.
DMS Serverless vs provisioned economics. For continuous long-running replication (weeks to months), Serverless typically saves 15 to 35 percent versus equivalent provisioned capacity because DCU scaling tracks actual workload demand rather than provisioning for peak. For short-burst replication (full-load that completes in hours), Serverless typically costs marginally more because of the cold-start scaling behaviour. The crossover point is typically around 7 to 14 days of active replication; longer than that, Serverless wins.
DMS Serverless rule of thumb
For AWS accounts created before 15 July 2025, the legacy free tier provides 750 hours per month of Single-AZ dms.t3.micro replication instance, plus 50 GB of included general purpose storage, for the first year. That covers continuous use of a single small replication instance, suitable for small databases or for testing larger migrations before production cutover. Accounts created after 15 July 2025 fall under the credit-based free tier instead: $100 in credits at sign-up plus up to $100 more for completing onboarding activities, spendable on any service including DMS.
For most production migrations the free allowance covers the planning and testing phase but not the production cutover. A typical pattern: use a free or credit-funded dms.t3.micro for source schema discovery and small-scale testing, then provision a larger dms.r5.large or dms.c5 for the production full-load and CDC. Either way the free tier meaningfully reduces the tooling cost for first-time AWS migrations.
DMS supports three replication modes that combine to handle different migration patterns. Full-load copies the source database to the target in a single bulk transfer; suitable for migrations that can accept downtime equal to the full-load duration. Full-load plus CDC starts with a bulk copy then maintains continuous change data capture replication until cutover; suitable for near-zero-downtime migrations. CDC-only assumes a bulk copy via a different tool then replicates ongoing changes; used for very large databases where DMS full-load is not the fastest path.
The cost shape varies by mode. Full-load is the cheapest pattern because the replication instance only runs for the bulk copy duration (typically days). Full-load plus CDC is more expensive because the replication instance runs continuously for the parallel-running window (typically weeks to months). CDC-only is similar to full-load plus CDC in replication instance time but eliminates the full-load DMS cost (the bulk copy is done via another tool, often AWS Snowball Edge for very large databases).
A representative DMS-specific cost build for a 5 TB SQL Server database migration to RDS for SQL Server, using full-load plus CDC with two weeks of parallel-running, dms.r5.large provisioned instance.
Worked DMS cost build, 5 TB SQL Server to RDS, 2 weeks parallel
| Cost line | Low estimate | Typical estimate | High estimate |
|---|---|---|---|
| DMS replication instance (dms.r5.large, 14 days) | $55 | $59 | $70 |
| Replication storage (100 GB gp3, 14 days) | $3.50 | $4.00 | $5.00 |
| EBS snapshots (replication state) | $0 | $5 | $15 |
| Data transfer (source to VPC endpoint, free if Direct Connect) | $0 | $150 | $450 |
| DMS task validation cost (one-off CPU spike) | $0 | $5 | $20 |
| AWS SCT analysis (free for SQL to SQL; SCT not strictly required) | $0 | $0 | $0 |
| Cutover-window DMS active (1-2 hours) | $1 | $2 | $5 |
| DMS total (excluding SCT remediation labour) | $59.50 | $225 | $565 |
The typical-column number, $225, illustrates how small the DMS tooling cost is relative to the overall database migration cost. The total cost is dominated by the partner labour ($30K to $100K per database for typical mid-market migrations), the validation and cutover work, and the destination RDS instance cost. DMS is rarely the line that matters in cost modelling; the tool's value is in operational reliability and the elimination of third-party tooling cost.
A second worked build, this time heterogeneous and long-running, to show where DMS Serverless earns its keep. A 20 TB Oracle estate migrating to Aurora PostgreSQL, eight weeks of full-load plus CDC parallel-running while the application is cut over wave by wave, billed on DMS Serverless at roughly $0.082 per DCU-hour with an average of 6 DCUs.
Worked DMS Serverless cost build, 20 TB Oracle to Aurora PostgreSQL, 8 weeks parallel
| Cost line | Low estimate | Typical estimate | High estimate |
|---|---|---|---|
| DMS Serverless replication (6 DCU avg, 56 days) | $520 | $660 | $900 |
| Peak-burst DCU scaling during full-load | $80 | $180 | $420 |
| Replication metadata storage | $5 | $15 | $40 |
| Data transfer (VPC endpoint, free with Direct Connect) | $0 | $120 | $380 |
| DMS validation tasks across the estate | $20 | $60 | $160 |
| DMS tooling total (excluding SCT remediation labour) | $625 | $1,035 | $1,900 |
The typical DMS tooling cost, roughly $1,035 for an eight-week heterogeneous migration, is again dwarfed by the schema-conversion remediation labour (the $60K to $300K Oracle to Aurora PostgreSQL band shown below) and the destination Aurora cost. The point of the Serverless model here is that DCU scaling tracks the long, low-throughput CDC tail rather than holding a provisioned dms.r5 idle for eight weeks, which is where the 15 to 35 percent saving versus provisioned comes from on parallel runs this long.
For heterogeneous migrations (different engine on source and target), DMS is paired with AWS Schema Conversion Tool (SCT). SCT analyses the source schema, generates the target schema, and produces a conversion report identifying objects that cannot be automatically converted. The remediation work for those objects is the largest cost line in heterogeneous database migrations.
Typical conversion rates by source-target pair (May 2026):
AWS SCT conversion rates by source-target pair
| Source | Target | Auto-conversion rate | Typical remediation labour per database |
|---|---|---|---|
| Oracle | Aurora PostgreSQL | 70 to 90% | $60K to $300K |
| Oracle | PostgreSQL | 75 to 92% | $50K to $250K |
| Microsoft SQL Server | Aurora PostgreSQL (via Babelfish) | 80 to 95% | $30K to $150K |
| Microsoft SQL Server | PostgreSQL | 75 to 90% | $40K to $200K |
| Microsoft SQL Server | MySQL | 70 to 85% | $40K to $200K |
| Sybase ASE | PostgreSQL or MySQL | 60 to 80% | $80K to $400K |
| IBM Db2 | PostgreSQL | 55 to 75% | $100K to $500K |
| Teradata | Amazon Redshift | 65 to 85% | $150K to $800K |
AWS DMS is one of the cheapest tooling line items in any cloud migration. The pricing model favours short, focused replications and DMS Serverless extends the favour to long-running replications with variable load. The cost discipline for DMS is rarely about DMS itself; it is about minimising the parallel-running window (which drives both DMS and destination database cost) and choosing the right replication mode for the downtime tolerance of the workload.
A. A typical DMS replication instance (dms.r5.large) costs $0.176 per hour on-demand in US East, or about $129 per month if continuously provisioned. For a 5 TB database migration with two weeks of replication, the DMS instance cost lands around $60 to $250 depending on instance class. Additional costs: storage on the replication instance (typically 100 GB for replication state at $0.115 per GB-month for gp2), data transfer out from AWS to a non-VPC source (standard egress rates), and any source-side network costs.
A. For AWS accounts created before 15 July 2025, the free tier provides 750 hours per month of Single-AZ dms.t3.micro replication instance use, plus 50 GB of included general purpose storage, for the first year. Accounts created after that date use the credit-based free tier instead ($100 in credits at sign-up plus up to $100 more for completing activities). The free allowance is intended for testing and small migrations; production migrations typically use larger instance classes (dms.r5.large or above) that fall outside it.
A. Four billing bases, and mixing them up is the commonest costing error. On-demand replication instances are billed per hour with no commitment. DMS Serverless is billed per DCU-hour, where one DCU equals 2 GB of RAM, and scales automatically. Database Savings Plans discount the rate in exchange for a committed hourly spend over a one or three year term. Homogeneous data migrations, meaning the same engine on source and target, are billed by the hour for the duration of the migration with no replication instance to provision at all. Check which basis a quoted rate uses before comparing it with another. Source: AWS DMS pricing page, checked September 2026.
A. DMS Serverless was made generally available in 2023 and provides DMS replication on a per-DCU (DMS Capacity Unit) per-hour billing model without the need to provision an instance class. The Single-AZ rate in US East is approximately $0.082 per DCU-hour. DCUs scale automatically based on workload demand. DMS Serverless typically saves 15 to 35 percent versus provisioned DMS for long-running migrations or migrations with fluctuating throughput. The trade-off is slightly higher peak billing during burst replication.
A. DMS supports a broad source list: Oracle, SQL Server, MySQL, MariaDB, PostgreSQL, MongoDB, Db2 LUW, Db2 z/OS, SAP ASE, and Amazon S3. Targets include all major AWS database services (RDS, Aurora, DynamoDB, Neptune, ElasticSearch, S3, Redshift, Kinesis, Kafka). Heterogeneous migrations (Oracle to PostgreSQL) require AWS Schema Conversion Tool (SCT) in addition to DMS. The supported combinations are documented on the AWS DMS supported sources and targets page.
A. Initial full-load throughput for DMS varies by source and target combination. Typical full-load throughput is 100 to 500 GB per hour for homogeneous migrations (e.g. SQL Server to RDS for SQL Server) and 50 to 200 GB per hour for heterogeneous migrations (e.g. Oracle to PostgreSQL). A 5 TB database full-load typically completes in 10 to 50 hours depending on source IO capacity and target ingestion rate. Change Data Capture (CDC) replication after full-load runs continuously until cutover.
A. AWS SCT is a free desktop tool that converts schema from one database engine to another. It is used in conjunction with DMS for heterogeneous migrations. SCT generates the target schema, identifies conversion gaps (objects that cannot be automatically converted), and produces a conversion report. SCT itself is free; the work of remediating conversion gaps is partner-led and typically costs $20K to $100K per database depending on schema complexity.
SQL Server to RDS ->
Largest DMS use case
AWS SCT cost ->
Schema conversion for heterogeneous
Oracle to AWS ->
DMS plus SCT for heterogeneous
AWS MGN cost ->
Server replication, not database
AWS Snowball cost ->
Bulk transfer for very large databases
AWS DataSync pricing ->
Incremental online transfer
Azure DMS pricing ->
The Azure counterpart, free Standard tier
AWS migration cost calculator ->
Full migration cost calculator
On-prem to AWS ->
MAP, EC2, Snowball
10 hidden costs ->
Detailed playbook
Updated 2 May 2026