Free Online Tenths Tracker

What are tenths of an hour?

A "tenth" is one-tenth of an hour, equal to exactly 6 minutes. When professionals say they bill "in tenths," they divide every hour into 10 equal increments rather than tracking minutes directly.

This creates a clean decimal system: 0.1 hours = 6 minutes, 0.5 hours = 30 minutes, 1.0 hours = 60 minutes. The decimal format makes multiplying time by hourly rates straightforward — no fraction conversion required.

Why do lawyers bill in 6-minute increments?

The American Bar Association established billing in tenths as the standard for legal timekeeping. The practice dates back to the 1970s when law firms transitioned from flat-fee billing to hourly rates.

Three reasons the legal industry adopted this system:

1. Calculation simplicity — Decimal math is easier than fraction math. At $400/hour, 0.3 hours is exactly $120.
2. Minimum billing threshold — A quick phone call or email review still generates 0.1 hours ($40 at $400/hour). This ensures small tasks are compensated.
3. Industry standardization — Clients expect invoices in this format. Courts accept it. Accounting systems support it.

Today, tenths billing extends beyond law. Consultants, accountants, architects, and freelancers use the same system for consistent client billing.

How to convert minutes to tenths

The standard method is to round up to the nearest 6-minute increment. Any time within a 6-minute window rounds to that tenth.

Examples:

• 2 minutes → 0.1 tenths (rounds up to 6 min block)
• 6 minutes → 0.1 tenths (exactly one block)
• 7 minutes → 0.2 tenths (starts second block)
• 15 minutes → 0.3 tenths (rounds 15 up to 18)
• 45 minutes → 0.8 tenths (rounds 45 up to 48)

Rounding practices: What's ethical?

Rounding up is standard practice and generally accepted, but ethical guidelines require reasonable billing:

• Don't bill minimum for every email — Multiple quick emails to the same client should be batched into one time entry.
• Consider fixed-fee alternatives — Routine tasks like document filing may warrant flat rates instead of hourly billing.
• Use accurate descriptions — Time entries should reflect actual work performed, not just category labels.

The ABA Model Rules of Professional Conduct require that legal fees be "reasonable." While rounding up is accepted, billing 0.1 hours for opening an email is considered overbilling by many bar associations.

Alternatives to tenths billing

Some firms use different increment systems:

• Quarter-hour (0.25) — 15-minute increments. Less precise, potentially overbills small tasks.
• Twelfths (0.083) — 5-minute increments. More precise but creates awkward decimals.
• Actual minutes — Exact time tracking. Most accurate but requires fraction math for hourly calculations.

Tenths remains the dominant standard because it balances precision with calculation simplicity. A 6-minute minimum is small enough to avoid significant overbilling while large enough to compensate for task-switching overhead.

Why use a tenths tracking app?

Manual time tracking creates two problems: under-billing (forgetting to log time) and calculation errors (converting minutes incorrectly).

Studies suggest attorneys lose 10-30% of billable time to poor tracking. At $300/hour billing 40 hours/week, that's $600-$1,800 in lost revenue weekly.

The Tenths app solves both problems. Timers run in the background so you never forget to track. Conversion is automatic — start, stop, and the app calculates tenths instantly. Export to PDF, Excel, or CSV for client invoicing.