@taxplot/calc

Tax calculations and access to tax data from tax·plot

What Is This?

@taxplot/calc is a plain JavaScript library used at tax·plot for tax-related calculations. It can retrieve tax data such as tax rates from our server and provides that data and calculation results in a format that is easy to use.

For now only US federal and some state tax data is available. This will be added to in the future.

Install

npm install --save @taxplot/calc

Usage

Access Token

Tax data required for tax calculations (brackets, rates, standard deduction amounts, etc.) is made available to @taxplot/calc via the taxplot taxQL GraphQL server and requires an authentication token to access. A token is automatically assigned when you create a user account at taxplot.com. Email support@taxplot.com with questions.

As with any access token, do not store yours in a publicly discoverable place.

The taxQL endpoint can be accessed directly at taxql.taxplot.com. To explore using GraphQL Playground, open taxql.taxplot.com in a web browser and paste your token in the HTTP HEADERS area at the lower left.

{
  "authorization": "PASTE_YOUR_TOKEN_HERE"
}

TaxPayer Object

Several taxplot functions require a TaxPayer object as a parameter. Create a new TaxPayer as follows.

import { TaxPayer } from '@taxplot/calc'

const someTaxPayer = new TaxPayer()

A new TaxPayer object is initialized as a US taxpayer filing federal-only as single in 2020, as follows:

      year: 2020,
      country: 'us',
      jurisdiction: 'federal',
      taxType: 'income',
      filingType: 'individual',
      filingStatus: 'single',
      deduction: null,
      income: null

Any of these values can be overridden on initialization or changed later.

Async Functions

taxBrackets([TOKEN], [TaxPayer])

The taxBrackets function returns a promise that resolves to an array of tax bracket objects corresponding to a given TaxPayer.

import { TaxPayer, taxBrackets } from '@taxplot/calc'

const taxPayer = new TaxPayer()

const brackets = taxBrackets(TOKEN, taxPayer)

brackets will resolve to:

[
{"__typename":"TaxBracket","amountsAbove":0,"amountsNotMoreThan":9700,"plusAmount":0,"rate":0.1},
{"__typename":"TaxBracket","amountsAbove":9700,"amountsNotMoreThan":39475,"plusAmount":970,"rate":0.12},
{"__typename":"TaxBracket","amountsAbove":39475,"amountsNotMoreThan":84200,"plusAmount":4543,"rate":0.22},
{"__typename":"TaxBracket","amountsAbove":84200,"amountsNotMoreThan":160725,"plusAmount":14382.5,"rate":0.24},
{"__typename":"TaxBracket","amountsAbove":160725,"amountsNotMoreThan":204100,"plusAmount":32748.5,"rate":0.32},
{"__typename":"TaxBracket","amountsAbove":204100,"amountsNotMoreThan":510300,"plusAmount":46628.5,"rate":0.35},
{"__typename":"TaxBracket","amountsAbove":510300,"amountsNotMoreThan":null,"plusAmount":153798.5,"rate":0.37}
]

standardDeduction([TOKEN], [TaxPayer])

The standardDeduction function returns a promise that resolves to a dollar amount corresponding to a taxpayer's standard deduction amount.

import { TaxPayer, standardDeduction } from '@taxplot/calc'

const taxPayer = new TaxPayer()

const deduction = standardDeduction(TOKEN, taxPayer)### standardDeduction([TOKEN], [TaxPayer])

deduction will resolve to:

12400

This value can then be assigned to taxPayer.deduction.

payrollRates([TOKEN], [TaxPayer], [payerType])

payerType can be EMPLOYEE, EMPLOYER, BOTH or SELFEMPLOYED and will determine whether payroll taxes relating to employees, employers or self-employed are returned by the function.

The payrollRates function returns a promise that resolves to an object containing the following:

• wageBase - the wage amount above which SS / OASDI is not applied in a given year
• additionalHIThreshold - The income amount above which additional Medicare / HI will be applied. This will change according to the taxpayer filing status.
• An array of PayrollTax objects, each containing:
  • name which will be OASDI, HI or HI-Additional.
  • rate, and
  • amount which will be null if no income amount is provided in the TaxPayer object.

import { TaxPayer, payrollRates } from '@taxplot/calc'

const taxPayer = new TaxPayer()

const payrollObject = payrollRates(TOKEN, taxPayer, 'BOTH')

payrollObject will resolve to:

{"__typename":"PayrollInfo","wageBase":142800,"additionalHIThreshold":200000,"payrollTax":
[
{"__typename":"PayrollTax","name":"OASDI","payer":"Employer","rate":0.062,"amount":null},
{"__typename":"PayrollTax","name":"HI","payer":"Employer","rate":0.0145,"amount":null},
{"__typename":"PayrollTax","name":"OASDI","payer":"Employee","rate":0.062,"amount":null},
{"__typename":"PayrollTax","name":"HI","payer":"Employee","rate":0.0145,"amount":null},
{"__typename":"PayrollTax","name":"HI-Additional","payer":"Employee","rate":0.009,"amount":null}
]}

Synchronous Functions

taxValues([TAX_BRACKET_OBJECT], [TaxPayer])

taxValues returns a three-value object containing a given taxpayer's marginal tax rate, calculated tax amount due, and calculated effective tax rate. In addition to the TaxPayer object, it requires a tax brackets object previously fetched using the taxBrackets function.

import { TaxPayer, taxValues, taxBrackets } from '@taxplot/calc'

const taxPayer = new TaxPayer({deduction: 12400})
const brackets = taxBracket(TOKEN, taxPayer)

const taxResult = taxValues(brackets, taxPayer)

taxResult will return:

{"marginalRate":0.24,"taxAmount":15198.5,"effectiveRate":0.151985}

Where a TaxPayer object's deduction amount is null, the taxValues function will assume a deduction amount equal to the appropriate standard deduction only when the first parameter is a token. When the first parameter is a tax brackets object, the function will assume deduction equals 0. To avoid confusion, assign TaxPayer.deduction prior to usingg the taxValues function.

marginalRate( ), taxAmount( ), and effectiveRate( )

Where only one of the taxValues values is needed, one can use one of the functions above.

marginalRate([taxBrackets], [TaxPayer]) is equivalent to taxValues([Token or taxBrackets], [TaxPayer]).marginalRate

and

taxAmount([taxBrackets], [TaxPayer]) is equivalent to taxValues([Token or taxBrackets], [TaxPayer]).taxAmount

and

effectiveRate([taxBrackets], [TaxPayer]) is equivalent to taxValues([Token or taxBrackets], [TaxPayer]).effectiveRate

payrollValues([payrollObject], [TaxPayer])

payrollValues returns an array of objects, each containing the payroll tax amounts of the various tax types and payer types as included in the provided payrollObject. For example, using the payrollObject returned from the payrollRates example above and a TaxPayer with income set to $300,000 will return:

{"OASDI":{"Employer":8853.6,"Employee":8853.6,"total":17707.2},
"Employer":{"OASDI":8853.6,"HI":4350,"total":13203.6},
"HI":{"Employer":4350,"Employee":4800,"total":9150},
"Employee":{"OASDI":8853.6,"HI":4800,"total":13653.6},
"total":26857.2}

Note that this object contains redundant data. This is so the user can use PayrollValuesObject.OASDI.Employer interchangably with PayrollVauesObject.Employer.OASDI.

bracketPlot([taxBracket], [deduction], [max Value])

bracketPlot is useful for turning a taxBracket object into something that is easily displayed visually. For example,

import { TaxPayer, taxBrackets, bracketPlot } from '@taxplot/calc'

const taxPayer = new TaxPayer()

const brackets = taxBrackets(TOKEN, taxPayer)

const plotBrackets = bracketPlot(brackets, 12400, 100000)

plotBrackets will give us:

[
  {"x":0,"y":0},
  {"x":12400,"y":0},
  {"x":12400,"y":0.1},
  {"x":22100,"y":0.1},
  {"x":22100,"y":0.12},
  {"x":51875,"y":0.12},
  {"x":51875,"y":0.22},
  {"x":96600,"y":0.22},
  {"x":96600,"y":0.24},
  {"x":100000,"y":0.24}
]

Neither the second nor third parameter (deduction and maxValue) are required.

The second parameter, deduction, is the amount of a taxpayer's income that is not taxed, thus shifting a plot of the tax bracket to the right by an amount equal to deduction. Where a deduction amount is not supplied it is assumed to be 0.

The third parameter maxValue is the rightmost income amount of the requested plot. Where maxValue is not supplied, it is assumed to be twice them amount at which the top tax bracket begins.

License

MIT © tax·plot