Inputs you will need

To run interest in Texas with DocketMath’s Interest calculator for US‑TX, you’ll need a small, consistent set of inputs. Think of this as a pre‑flight checklist:

Core date inputs

• Start date
  The date interest begins to accrue. Often:

  • Date of judgment
  • Date of breach/default
  • Date payment became due under a contract
  • Date of injury or loss (for certain statutory interest)

• End date
  The date through which you want interest calculated. Common choices:

  • Today’s date (for “as of now” calculations)
  • A specific settlement date
  • A projected payment date

Money amounts

• Principal amount
  The dollar amount the interest is calculated on:

  • Judgment amount
  • Unpaid invoice balance
  • Contract damages or settlement principal

• Adjustments to principal (optional)
  If you need to reflect changes over time:

  • Additional advances or draws
  • Principal paydowns or partial payments
  • Credits, write‑offs, or refunds

DocketMath lets you model these as dated changes, so the principal can step up or down over the life of the calculation.

Rate inputs

• Interest rate type
  You’ll typically choose between:

  • Fixed rate (e.g., 6% per year)
  • Variable rate (e.g., “prime + 3%,” or a rate that resets on specific dates)

• Interest rate value(s)
  Depending on your scenario:

  • Contract rate (from a note, loan, or agreement)
  • Statutory rate (e.g., Texas post‑judgment interest)
  • A blended or negotiated rate for settlement modeling

• Rate change dates (for variable rates)
  If the rate changes:

  • Effective dates for each new rate
  • The new rate value for each period

Compounding and day‑count

• Compounding frequency
  How often interest is added to principal:

  • Simple (no compounding)
  • Annual
  • Monthly
  • Daily

• Day‑count / accrual convention
  How days are counted:

  • Actual/365
  • Actual/360
  • Actual/Actual
  • 30/360 (less common for Texas statutory, more common in some finance contexts)

These inputs can materially change the total interest even if the nominal rate is the same.

Texas‑specific options you may need

Depending on what you’re modeling in Texas:

• Pre‑judgment vs. post‑judgment interest

  • Separate start dates and, sometimes, separate rates
  • Different treatment for different claim types or time periods

• Rate caps or statutory limits

  • Maximum allowable rates under Texas law
  • Contractual usury savings clauses, if you’re modeling contract interest

• Excluded periods (if applicable)

  • Periods where interest does not accrue (e.g., certain court‑ordered stays, tolling periods, or agreed “no interest” windows)

Output‑focused options

These don’t change the legal rules, but they change how you see the results:

• Rounding preferences

  • Round to cents at each step vs. only at the final total
  • Rounding mode (standard, always up, etc.)

• Breakdown granularity

  • Interest by year
  • Interest by month
  • Interest by rate period or event (e.g., pre‑ vs. post‑judgment)

These options make it easier to explain and document your interest figures, especially when you’re using Explain++ or sharing the output with opposing counsel or a client.

Where to find each input

Below is a practical guide for where these inputs typically live in a Texas matter and how changing them affects your result.

For many users, the fastest workflow is:

1. Pull dates and principal from the judgment or contract.
2. Confirm rate and compounding from the same document or applicable statute.
3. Export payment/ledger history (if you have partial payments or principal changes).
4. Decide on a consistent end date for all your scenarios.

Once you have those, you’re ready to plug everything into the DocketMath Interest calculator for US‑TX.

Run it

Here’s a practical, repeatable way to run Texas interest in DocketMath and understand how each input drives the result.

1. Set the jurisdiction and template

1. Open the Interest calculator:
   → /tools/interest
2. Select Jurisdiction: Texas (US‑TX) or the closest Texas‑specific template available.
3. Choose the scenario type:

   • Pre‑judgment only
   • Post‑judgment only
   • Combined, with separate phases

This choice determines which fields you see and how DocketMath structures the timeline.

2. Enter principal and date range

1. Enter the principal amount.
2. Enter the start date (when interest begins).
3. Enter the end date (through which you want interest calculated).

If you are modeling multiple scenarios (e.g., different settlement dates), keep all inputs the same except the end date. That isolates the effect of time.

3. Add rate and compounding details

1. Choose fixed or variable rate:

   • For a fixed rate, enter the annual rate (e.g., 5.00%).
   • For a variable rate, add each rate period:

     • From date
     • To date (or leave open to end date)
     • Rate for that period
2. Set compounding:

   • Simple (no compounding) for many statutory or judgment scenarios
   • Monthly or annual if required by a contract
3. Pick a day‑count convention consistent with your documents or assumptions.

You’ll see the daily accrual and total interest update based on these choices.

4. Model Texas‑specific phases and events

If your Texas matter has multiple phases:

• Add a pre‑judgment period with its rate and dates.
• Add a post‑judgment period starting on the judgment date, with its own rate.
• Insert principal changes:

  • Payments as of specific dates (reducing principal).
  • Additional amounts added (e.g., later‑incurred damages or costs, if you are modeling them as principal).

Each event creates a segment in the timeline. DocketMath tracks interest separately for each segment and then aggregates it.

5. Inspect the breakdown

Once the inputs are set:

• Review the summary totals:

  • Total interest
  • Total days
  • Effective blended rate (if shown)
• Open the Explain++ or detailed breakdown:

  • Interest by period (e.g., each rate or phase)
  • Interest by year or month
  • Effect of each payment or adjustment

If something looks off (for example, interest jumps unexpectedly in a given year), check:

• Whether a rate change date is correct.
• Whether a payment was entered as a principal increase instead of a decrease.
• Whether the compounding or

Inputs you will need

Use this checklist to gather the core inputs before you run the Interest tool.

• principal or judgment amount
• interest type (pre- or post-judgment)
• rate and compounding method
• start date and end/as-of date
• payments or credits that reduce principal
• day-count convention

Where to find each input

Most inputs live in the case file, contracts, or docket entries. Dates usually come from the triggering event notice; rates and caps come from governing documents or statute; and amounts come from the ledger or judgment. Record the source for each value so the run is reproducible.

Run it

Enter the inputs in DocketMath and run the Interest calculation to generate a clean breakdown: Run the calculator.

When rules change, rerun the calculation with updated inputs and store the revision in the matter record.

If an assumption is uncertain, document it alongside the calculation so the result can be re-run later.

Related reading

• Interest rule lens: Maine

• Inputs you need for deadlines in Australia

• Common interest mistakes in Rhode Island

• Why we started the DocketMath blog