SLN Function in Apple Numbers: Syntax and Worked Examples

• Introduced: Documented in Apple’s Formulas and Functions Help 15.4; the first release and introduction date remain unknown.
• Availability: Currently documented for Numbers in that 15.4 documentation edition; it does not establish a final supported-version endpoint.
• Scope: Shared iWork function reference. Client-specific introduction dates and older Mac, iPad, iPhone and iCloud behavior are not established here.
• Checked: October 14, 2026, against the official SLN reference. Documentation and independent arithmetic checks; no native Numbers test.

=SLN(cost, salvage, life)

All three numeric arguments are required:

• cost: the asset’s starting cost, zero or greater.
• salvage: the expected value remaining after its useful life, zero or greater.
• life: the number of depreciation periods, greater than zero. Apple explicitly permits a fractional life such as 5.5.

The straight-line calculation is (cost-salvage)/life. SLN returns one period’s expense, not accumulated depreciation and not the asset’s remaining carrying value. It has no period-number argument because the amount is constant under this model.

The unit of life controls the unit of the answer. Use 4 for a four-year life when calculating annual expense, or 48 for the same life measured in months when calculating monthly expense. Changing cell formatting does not perform that conversion.

Create a blank table named Examples with four columns A:D and seven rows. Label the headers Cost, Salvage, Life, and Depreciation per period. Enter A2:C7 as follows:

Put =SLN(A2,B2,C2) in D2 and fill through D7. Use ordinary numeric inputs, without currency symbols embedded as text. Display the results as numbers or currency with two decimal places.

Rows 2 and 4 describe the same total allocation using annual and monthly periods. The monthly amount 250 multiplied by 12 equals the annual amount 3,000. Row 5 uses the explicitly supported fractional life; the result is 2,000 for one full life-unit, not a complete rule for posting a final half-period.

Apple notes that the displayed currency depends on Language & Region settings. A dollar, euro or other symbol is a display choice here. SLN does not convert currencies; cost and salvage must use the same currency and scale.

Create a separate table named Schedule with at least nine columns A:I and six rows. Keep the Examples table unchanged. Put Parameter in H1 and Value in I1, then enter:

Label A1:E1 Year, Opening value, Expense, Closing value, and Cumulative expense.

1. Put 1 in A2. Enter =A2+1 in A3 and fill through A5.
2. In B2 enter =$I$2.
3. In C2 enter =SLN($I$2,$I$3,$I$4) and fill through C5.
4. In D2 enter =B2-C2 and fill through D5.
5. In B3 enter =D2 and fill through B5.
6. In E2 enter =SUM($C$2:C2) and fill through E5.

In C6, enter =SUM(C2:C5). The total 12,000 equals I2-I3, and the final closing value 1,000 equals the assumed salvage value. The SUM function check helps expose omitted or extra schedule rows.

Do not extend the expense formula indefinitely. SLN alone does not know that a separate schedule has already reached year 4; another row using the same arguments still asks for the same single-period amount. Control the schedule’s period count explicitly.

For =SLN(10000,0,6), the unrounded amount is 1,666.666… per year, displayed as 1,666.67. Six displayed amounts multiplied as if they were exact produce 10,000.02. That is a rounding effect, not additional depreciable cost.

Preserve full precision in analytical formulas. If a posting workflow requires rounded entries, determine an explicit rounding and final-adjustment policy rather than silently treating formatted display values as the stored calculation.

SYD allocates more expense to early periods under a different method. A similar total over the asset’s life does not make the year-by-year amounts interchangeable. The choice of accounting or tax method depends on the applicable rules and circumstances; this tutorial only demonstrates the arithmetic.

Use nonnegative cost and salvage, and a positive life, as documented. The short Apple entry does not enumerate exact error tokens, text/blank coercion, or the intended interpretation when salvage exceeds cost. This guide uses salvage no greater than cost and does not promise a particular result outside that modeling range.

A fractional life is supported, but a start date, first-year fraction, disposal date or midlife estimate change is not an SLN argument. Such events require a separately defined schedule. They cannot be inferred from the formula name or from the local currency format.