Compound interest calculator
Compound interest calculator - final balance, interest earned and year-by-year growth for a principal, rate, years and optional monthly contribution
Answeringour last check, 2026-10-18
1 of 1checks answered this week
386 msmedian answer time
$0.01listed price per call
$0.01price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://saylorinnovations.com/api/calc/compound
| Category | Market data |
|---|---|
| Provider host | saylorinnovations.com |
| Networks | eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 2 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-18 | valid payment request | 402 | $0.01 | 386 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"monthly_contribution": "250",
"principal": "10000",
"rate": "6.5",
"years": "20"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST",
"PUT",
"PATCH",
"DELETE",
"HEAD"
],
"type": "string"
},
"queryParams": {
"properties": {
"monthly_contribution": {
"description": "optional, default 0",
"type": "string"
},
"principal": {
"description": "Starting amount",
"type": "string"
},
"rate": {
"description": "Annual interest rate in percent",
"type": "string"
},
"years": {
"description": "Years to grow",
"type": "string"
}
},
"required": [
"principal",
"rate",
"years"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"annual_rate_percent": {
"description": "Annual rate as a percentage",
"type": [
"number",
"null"
]
},
"checked_at": {
"description": "Time the check was run (UTC)",
"type": [
"string",
"null"
]
},
"compounds_per_year": {
"description": "Compounds per year",
"type": [
"number",
"null"
]
},
"effective_annual_rate_percent": {
"description": "Effective annual rate, as a percentage",
"type": "number"
},
"final_balance": {
"description": "Balance at the end of the period",
"type": "number"
},
"interest_earned": {
"description": "Total interest earned",
"type": "number"
},
"method": {
"description": "Method used",
"type": [
"string",
"null"
]
},
"monthly_contribution": {
"description": "Monthly contribution",
"type": [
"number",
"null"
]
},
"principal": {
"description": "Starting principal amount",
"type": [
"number",
"null"
]
},
"total_contributions": {
"description": "Total contributions",
"type": "number"
},
"yearly": {
"description": "Yearly values",
"items": {
"properties": {
"balance": {
"description": "Balance in whole units",
"type": "number"
},
"contributions": {
"type": "number"
},
"interest": {
"type": "number"
},
"year": {
"description": "Calendar year",
"type": "number"
}
},
"type": "object"
},
"type": "array"
},
"years": {
"description": "Years covered",
"type": [
"number",
"null"
]
}
},
"required": [
"final_balance",
"total_contributions",
"interest_earned"
],
"type": "object"
},
"type": {
"const": "json",
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}